We have constantly had active campaigns in the last weeks, and a steady increase of registered users.
But it all really depends on what type of website you have, what ad size you are running, which country your visitors are from and so on.
Recently we have been selling ad inventory to partnering advertising network, but they are mostly interested in high-volume websites.

We see that unique (and popular) websites usually get a lot of interest, where as faucets (and similar) gets the least interest from advertisers.

I guess that's as good as an answer I can give you.