Do some of the most popular microstock site have too much pictures? Most of now have more than 2 millions pictures online and still growing.
I think, in my opinion, it can be the time to delete some of the oldest files who don't sell since a while or don't meet the latest increased quality that we are talking about sometimes in the last months.
Lately, even whit a small portfolio, I deleted some files at Dreamstime that was accepted when I started. Don't have to say that they won't be accepted today.
Maybe 2 millions is not too much, but when they are going to hit the 4 millions or a thing like that... I don't have some numbers, but I wonder to know if there's a good buying/growing ratio?