Make money online

So a few years on from the start of my first steps as an internet entrepreneur (!!) what have I learned? Has it been worthwhile? and more importantly: Is it possible to make money online?
I think I was always skeptical about how much could be made online, and was pleasantly surprised to discover that you can make a bit without selling your soul entirely... I run a service that ONLY has a presence online and am happy to report that I have been reasonably successful making a little money with that service. I really started blogging to promote this service and talk about my experiences creating a website.
I moved on then to create some more blogs, and then some more blogs as I started to examine the earning potential of different niches. Earnings from these have come in the form of sponsored posts and both static and dynamic adverts. Success rates with these methods vary according to the popularity of the site, the 'quality' of the content and especially with PageRank.
I get a certain amount of revenue for context-sensitive ads (say around $50pm), and an amount for fixed ads (around $45pm). Sponsored blog posts vary a lot for me, but have averaged about $150pm lately. I figure that means that with my experience and a few hours a week bashing at a keyboard, I can earn around $250pm if we take into account some text-link sales here and there..
Add this to the revenue that my website brings in and it is enough to stave off the worst effects of the credit crunch. I know of people who spend full-time hours with online earnings and the general conclusion would have to be that there is often no one single thing that is a big earner, but combining several different sources can provide earnings equivalent to a wage if you are prepared to put the hours in.
My resources are mostly contained in the following links:
The TurnOnePoundIntoOneMillion blog (Rachel makes a decent income from online earnings), and the online earnings pages at Livewyre.net which helps to sort out the scams from the real proven earners.