But the transaction still involves a seller (you) and a buyer (the advertiser). The click is still worth the same to the consumer (zero) but to the advertiser, it's worth a lot less if they are not going to buy.
I don't think visitors are clicking less. I think advertisers are bidding lower.
I don't know when the economy will turn around, but I'm guessing online advertising will be a leading indicator rather than a trailing one -- the recovery should be preceded by a lot of speculation that there is going to be a recovery, which may lead businesses to increase their ad spend to try to get a jump on it.