On the outset
This sounds like an easy way to make money, but, I can imagine the team behind these virtual people isn't small and a lot of time is spent on making the accounts appear attractive to people to in turn make them attractive to advertisers, far more time than you could do so yourself.
Which is a shame, as I do like the sound of pinching out a picture every few days yet making enough to buy a private island.. (said in the middle of ten minute break from what will undoubtedly be another eighteen hour day..)
Biting the hand that feeds IT
