Yea one shouldnt be too dependent on one source of income. I want to be about 33% adsense and find other services to put ads on my websites
I agree on this although the list can be greatly expanded. It takes time to master each revenue stream. You can't jump around from one to another and be successful. Master one, then move to the next. Currently I am going on at least 20 different revenue streams and they aren't all PPC.
Hmm... Actually, thats a good idea. Never thought much on it. I surely need a brainstorming session soon with my team.