I've used Adsense for several years. My revenues dropped by about 75% this year as well. I've not "given up," but I've been looking at other avenues of residual income.
My Amazon.com reseller account went down to less than $10 per month this year, which is a huge drop. I'll probably be pulling all their ads off my sites soon.
Adwords... I don't use it. I've found that in competitive areas, the competition clicks more than potential clients. I just did a test two months ago, and spent over $200 in two weeks, without one extra real lead. I just don't use it.
On the consumer side, I completely ignore any pay per click ads unless I"m gaging them for a new campaign, and have found that my clients do the same. They know which ones are the paid ads (especially when surfing google), and reject them for "real results."
It's tough to determine where to go though. Commission Junction has always been a big waste of my time, I've never made anything worthwhile compared to the time their system takes.
I've added Kontera to some of my sites, but the results are mixed. It's easy to set their stuff up, but the revenues haven't been that great.
If you find anything that looks good out there, tell me, and I will as well...
