Every now and then a new agency comes around. Then its gone...

It is so easy - host pixels, sell pixels. So how could they possibly close their doors when image sites have the potential to at  worst sit idle indefinitely? Billions of people on the internet...you'd think success was a birthright to any new image site. Why do they fail? 

Almost total lack of marketing (it would cost a fortune to lure people off the existing sites, worldwide).

And/or total cluelessness about the business (particularly legal aspects, in regards to contracts or releases etc), as has been demonstrated often enough by wannabes soliciting contributors on here, who can't or won't answer even the most simple questions.

Most of us have been bitten hard at least once, so any new kid on the block has to have impeccable credentials right from the start.

Most new businesses fail, no matter what kind. Even Oringer had a string of failures before he hit success with Shutterstock.