I had one particular ad (for merchant accounts) through CJ that paid pretty well. I did more than $500 a month with that offer for about a year, back in 2005.
I haven't touched the site since, but every year that ad earned less and less. Finally last year I stopped receiving checks from CJ and now they closed my account for inactivity. Just seems kinda funny that nothing has changed on my end but I went from bringing in the dough to not even justifying an open account.