I'll agree with Lowry - I see sales off of older sites more often now, it seems almost as if they have to 'season' before they make a sale anymore
I'll notice when I go on a submitting spurt I do tend to see more $$ a couple weeks down the road (then I get sidetracked and don't sub for a week, which sucks lol) I also switched to mainly revshare not too long ago and am very grateful for that now.
I've been doing a lot of work on my LL, and am starting to see revenue from that too, but it's taken me 3 years to get here, so don't get discouraged. Everyone always says it here, but it's true - just keep building stuff and it'll pay off