This is one of the reasons I joined wickedfire... I've been a web designer for 12 years but never pulled off making any money via IM. Now I've been working on mini sites, and a couple other sites.
Finally got some SEO working and a new site is getting me 500, 700, 950 unique visitors over the last three days. I put adsense on and CPALead for a free ebook download. Adsense gave me 0.14, 0.39, 0.48 - CPA gave me 1.28, 1.46, 2.14
I know it's a game of try and adapt. CPA does seem better, but takes a bit more effort. AdSense is depressing at the moment. I had thought of doing the mini-site network thing and try to build up 100 sites or whatever but with my background in design, I think it may be better to build up 25, then 50 slightly higher quality sites and work SEO to drive the traffic.
I guess the biggest question is always how do I get traffic to convert, but the answer can't be straight because that question is a misnomer. The real question is what traffic do I get, and what platform would provide the best conversions. Still requires a lot of trial and error.
And 99% of the people that have done that aren't gonna hand it out like cookies in their kidnap van. That doesn't mean that there's nothing to learn here - it just means we need to discover the right questions to ask.