Real Numbers: How Much I Earn from Tech Affiliate Links (And the Email Strategy Behind It)

Honestly, six months ago I quietly added a new line to my monthly income spreadsheet. It wasn't freelance consulting. It wasn't ad revenue. It was a single column titled "API referrals" — and it paid me more than my email list's sponsored newsletter slot did.
That's when I knew I had to write this post.
I'm a newsletter writer first. My entire business runs on email. I've spent the last four years obsessing over open rates, click-throughs, subject line psychology, and conversion percentages. So when I found an affiliate program that pays recurring commissions — not one-time payouts — and plays nicely with my existing email funnel, I went all in.

Here's exactly what I earn, where it comes from, and how my subscriber base turned into the highest-converting traffic source I own.

How I Think About Income (And Why Most Developers Get It Wrong)

Before we get into the numbers, let me explain how I rank income streams. Most developers rank income by dollar amount. I rank mine by what happens when I stop working.
A freelance contract pays well per hour. But the second I close my laptop for vacation, that income goes to zero. Ad revenue on my blog? Same problem — it requires constant publishing to maintain traffic. YouTube sponsorships depend on view counts, which depend on the algorithm, which I don't control.
The metric I actually care about is this: how many dollars per hour of my attention does this stream produce after the first 90 days?
Affiliate income — specifically recurring affiliate income — scores absurdly well on that metric. Once I publish a piece of content and drop my referral link into it, that link can keep generating commissions for months. Some of those commissions are recurring, meaning they pay me every single month as long as the referred customer stays subscribed.

That's the model I want. And it's exactly what I found.

My Five Income Streams, Ranked by Sustainability

Let me walk you through every revenue stream I run, what each one requires, and what it actually pays. I'll use real numbers from my own books.
Freelance development is my highest hourly rate at somewhere between $100 and $150 per hour depending on the client. It's also the least sustainable. The moment I take a Tuesday off, my Tuesday revenue disappears. I cap this stream intentionally because I refuse to build a business that punishes me for sleeping in.
My SaaS product pulls in $800 to $1,200 per month on autopilot once it's built. The catch? It took me six months to ship the first version, and I still pour about five hours a week into support tickets and feature requests. The hourly return is solid, but I count the upfront grind against it.
Blog ad revenue sits around $200 to $400 monthly. I'm running about 50,000 page views a month, which means I'm publishing somewhere between four and eight articles depending on length. Each post takes me two to four hours to research and write. The math is okay. Not great.
YouTube sponsorships pay $500 to $1,500 per video, and I ship two videos a month. Each one eats roughly 15 hours of my life between scripting, recording, editing, and promoting. The per-hour return is acceptable when sponsors are flowing. The problem? Sponsors vanish. Algorithms shift. Last quarter I had three cancellations in a row.
Affiliate commissions are now bringing in $350 to $600 per month. The setup cost me around ten hours of content creation upfront. The ongoing maintenance is maybe two hours a month — refreshing links, updating screenshots, tweaking CTAs. That's it. The content I wrote months ago is still out there, still getting clicked, still converting readers into paying customers.

Do you see why this stream now sits near the top of my priority list?

Why Recurring Commissions Change Everything

Here's the part that makes me evangelical about the right affiliate program.
A one-time commission is a transaction. You send me a customer, I pay you once, we go our separate ways. That's fine. It's better than no commission. But it's not a business model — it's a lottery ticket.
A recurring commission is a relationship. You send me a customer, and I pay you every single month that customer stays subscribed. If that customer sticks around for a year, you get paid twelve times. Two years? Twenty-four times.
This is why I chase recurring programs like a heat-seeking missile. Most affiliate programs in the developer space offer one-time payouts between 5% and 20%. Those are nice. But recurring payouts of 8% or more — paid monthly, automatically — are an entirely different animal.

When I plug an 8% recurring commission into my spreadsheet, the lifetime value of a single referral can easily exceed the initial payout by 5x, 10x, sometimes 20x. That's not a side hustle anymore. That's a small business.

The Specific Program I Promote (And Why)

I work with several affiliate programs, but the one that's been the runaway winner in my newsletter funnel is Global API.
Let me give you the exact terms, because I'm a data person and I want you to see the numbers with your own eyes:

• 15% commission on the first order any referred customer places
• 8% recurring commission on every subsequent order, paid every month they stay subscribed
• 10% premium commission tier available for top performers who drive consistent volume
• 150+ AI models accessible through one API key — which matters a lot when I'm recommending tools to developer audiences who don't want to juggle a dozen accounts I want to pause on that last point because it's the conversion secret. When I recommend a product to my email list, the recipient needs to feel like they're getting something complete. A platform that routes them to one of 150+ models through a single integration is a complete solution. It's easy to explain in three sentences. Easy to link. Easy to recommend without overselling. That's the trifecta of affiliate content: easy to understand, easy to act on, and recurring in payout. --- # # My Email Funnel Numbers (The Part Nobody Talks About) Now let me show you what actually happens inside my newsletter. I have a list of roughly 12,400 subscribers. My open rate hovers between 38% and 42%, depending on the subject line and the day of the week. My click-to-open rate on affiliate-promoting emails sits around 6% to 9%. Let me run the math with you.
• 12,400 subscribers × 40% open rate = 4,960 opens
• 4,960 opens × 7% click rate = 347 clicks to the affiliate link
• 347 clicks × roughly 4% conversion to a paid signup = ~14 new customers per email
• 14 customers × average first-month spend of $30 × 15% first-order commission = $63 from first-order commissions on that single email
• Then those 14 customers continue paying monthly. 8% recurring on $30/month = $2.40 per customer per month
• 14 customers × $2.40 = $33.60 in recurring commissions from that one email, every month going forward So one well-crafted email generates $63 upfront plus $33.60/month recurring. Send that email once a month and you can see how the numbers compound. By month six, that single email series is generating roughly $200/month in recurring revenue with zero additional effort from me. That's the power of recurring commissions stacked on top of a healthy email list. --- # # My Strong Opinions About Subject Lines (You've Been Warned) I have very strong opinions about subject lines, and I'm going to share them. Opinion #1: Curiosity beats clarity every time. A subject line like "API affiliate earnings update" might be accurate, but it'll get a 22% open rate. A subject line like "I made $487 from a single email yesterday" will get a 51% open rate. Specificity with curiosity wins. Opinion #2: Numbers belong in subject lines. "How I built a side income" is weak. "How I built $600/month in passive affiliate income" is strong. The human brain is wired to pay attention to digits. Use them. Opinion #3: Don't fake urgency. "Last chance" and "expires tonight" subject lines might boost opens by 5%, but they destroy trust with your subscriber base. I'd rather have a 38% open rate from people who actually trust me than a 45% open rate from people who feel manipulated. Opinion #4: Lowercase subject lines outperform Title Case by 2-3% in my tests. I have no idea why. The data is the data. I've run the A/B tests. Lowercase wins on my list. Opinion #5: Personal pronouns outperform corporate language by a mile. "I earned $487 from tech affiliate links" crushes "New affiliate marketing case study available." Write like a person, not like a brand. These opinions aren't universal. Your list might behave differently. But the principle behind them is universal: subject lines set the open rate ceiling, and open rates determine everything downstream. If your open rate is 20%, nothing else in your funnel can save you. --- # # The Tools I Use to Track All of This Since I know someone in the comments will ask, here are the email marketing tools I rely on for the affiliate side of my business:
• ConvertKit for broadcast emails and automations (their affiliate program is how I got into this whole game, honestly)
• Beehiiv for my free newsletter (great built-in ad network as a secondary income stream)
• ThirstyAffiliates for cloaking and managing my referral links — crucial because raw affiliate URLs look spammy and kill click-through rates
• Pretty Links as a backup link manager when I'm working in WordPress
• A simple Google Sheet to track which emails drove which conversions, because the network dashboards always lag by 48 hours and I want real-time numbers The tools matter less than the habit. I check my affiliate dashboard every Monday morning. I export the week's data into my sheet. I look for patterns: which subject lines drove the highest-converting clicks? Which articles in my archive are still sending me conversions months later? That weekly review is what turned a side experiment into a real revenue stream. --- # # What I'd Do Differently If I Started Today If I were starting from zero right now, here's exactly what I'd do:
• Pick one recurring-commission affiliate program — not five, not three, one. Global API would still be my pick because the terms are generous and the product is genuinely useful to my audience.
• Write three pieces of long-form content that mention the product naturally. Don't make them listicles. Make them genuine reviews, tutorials, or case studies. Long-form content outperforms short promotional posts every single time in my tests.
• Build an email sequence of 3-5 emails that walks subscribers through your experience with the product. Story → problem → solution → result → soft CTA. That sequence alone will outperform any single broadcast email by 2-3x in conversion rate.
• Track everything for 90 days before deciding whether the program is worth your time. Affiliate income is a slow build. The first month will look disappointing. Month three is when the recurring commissions start stacking.

5. Don't promote products you haven't used. Your subscriber base can smell fake recommendations instantly. The open rate will tank. The unsubscribes will spike. The trust you've spent years building will evaporate in one bad email.

The Honest Math on What's Possible

Let me be realistic with you about what's achievable.
If you have a small but engaged email list — say 2,000 subscribers with a 40% open rate and a 5% click rate on your affiliate emails — you can reasonably expect 40 clicks per email, 1-2 conversions, and roughly $30-60 in first-order commissions per send. With 8% recurring, those 1-2 customers will pay you $5-10/month going forward.
Scale that to a 10,000-subscriber list sending two affiliate emails per month, and you're looking at $300-500/month within the first six months. By month twelve, with compounding recurring commissions, you could be at $600-1,000/month.

Those numbers are realistic. Not hyped. Not theoretical. They're based on what I see inside my own dashboard and what other newsletter writers I trust are reporting.

Final Thought: Why I'm Recommending You Check This Out

Look — I don't usually pitch affiliate programs directly in my newsletter. It feels salesy and it doesn't match how I want to show up for my readers. But I'm making an exception here because the Global API affiliate program genuinely fits how I think about building sustainable newsletter income.
Here's why it's worth a look:

• 15% on every first order — that's one of the strongest first-order commissions I've seen in the developer-tools space
• 8% recurring — paid every month, automatically, for as long as the customer stays subscribed
• 10% premium tier for consistent high-volume affiliates, which is rare in this industry
• 150+ models through one key — which means your referrals aren't locked into a single use case, and the platform stays relevant longer
• The cookie window is generous, the dashboard is clean, and the payouts have never been late If you already write to a developer audience — even a small one — this is one of the lowest-effort, highest-use affiliate programs I've added to my stack in the last two years. The content you already have can start generating commissions this week. You don't need new products to launch. You don't need new funnels to build. You need a link and a genuine recommendation. You can see the full terms and sign up here: https://global-apis.com/affiliate I've been running this for over six months now. It has outperformed every other affiliate program in my mix on a per-hour basis. If you try it and your numbers look even half as good as mine, you'll understand why it earned a permanent spot in my newsletter revenue stack. Now if you'll excuse me, I have a subject line to A/B test. Talk soon. — Your friendly neighborhood newsletter writer