I actually found that GitHub Pages didn't scale well at all -- during peak traffic, response times slowed to over 10 seconds. This was my main motivation for the switch. Nginx (even on a micro EC2) should be able to handle very high load without the need to scale. S3 is definitely a viable option as well (and I'm not suggesting you shouldn't use it) but I find that an EC2 was a better fit for my needs.
It's not free, that's true. But it's very cheap, especially when paired with Amazon's 1-year free usage tier. But the main benefit is the added control over the web server.
Great article. One thing I'm struggling with as a freelancer is finding clients - I'm based in a small town in New Zealand, so I'm a long way from the opportunities in the UK and USA. How do you track down and approach new clients (who are likely to be happy with your rate)?
I also feel like being in New Zealand hampers my ability to charge a higher rate. I don't know for sure, but I suspect that companies here are used to paying lower rates simply because there's less talent here than overseas.