I’ll never forget my first cheque from Google. An envelope arrived with the familiar multicoloured logo, posted from 1600 Amphitheatre Parkway, Mountain View. Inside was a cheque for $130.87 (£65). A few months earlier I’d pasted a few lines of code into my little music gear blog and some small ads appeared. Now, miraculously, I was being paid.

I’d been running the blog for about five months, probably spending an average of two hours a day on it. If I’d spent those hours working at McDonald’s for minimum wage, I’d be looking at a cheque for £1,605. Maybe this wasn’t my passport to riches.

Unless you’re a blogger yourself, you’ve probably never heard of AdSense. It’s Google’s hugely profitable advertising system. Anyone with a website – whether it’s a free homepage or a huge commercial site – can sign up and download a couple of lines of code. Paste the code into your page, and the system starts displaying ads. Because Google knows exactly what is on your page, it chooses appropriate ads. My blog, musicthing.co.uk, is about esoteric music gear. Most of the ads are for guitars or keyboards, but sometimes the system gets it wrong, and starts posting ads for $50,000 DNA synthesisers.

I get paid every time someone clicks on an ad. The amount is calculated by a complicated auction algorithm, but it’s usually between 20 cents and $2 per click. The more readers you have, the more clicks you get, the more money you make. You don’t actually get paid until you’ve earned $100. In 2006, this meant Google was sitting on $370 million of unpaid earnings.

Music Thing has been a modest success. According to one list, it’s the seventh most read British-owned blog in the world. In 2006 I made just over £3,000 from the blog. That was a lot more than I’d spent buying myself music gadgets, so I was pleased. Then I heard about a friend of a friend who runs a sports health advice site and apparently earned “enough to pay his mortgage”.

Suddenly I felt that my blog was underperforming and I spent many late nights building the Music Thing Shop – a collection of links to online music gear dealers, with photos and carefully written descriptions. I asked readers to suggest how they’d like it to work, and was hopeful of success. Unfortunately success never came, and I stopped looking at the figures after learning that I’d earned $6 in the first month.

There’s endless advice online about how to make money blogging. Many people get obsessed with black arts and acronyms, from pings and trackbacks to SEO, PPC and RSS. “Actually write something interesting” is usually some way down the list.

I got into blogging because I enjoy finding geeky music gadgets and telling the world about them. The satisfaction I get isn’t a £65 payment from eBay dropping into my account. It comes when I check my e-mail, and every morning find messages like this one: “Hi Tom, I’m sure you’ll enjoy this video of Hermann von Helmholtz’s beautifully crafted wood and brass double siren from 1863.”

Times recommends

• Sony Reader could kill off the book
• Make 3D images with your own camera
• Lifelike animation heralds new era for computer games