At GDC 2012, Ted Regulski, the manager of SCEA Developer Relations, revealed that there are now around 90 million PlayStation Network accounts worldwide. Of course, as the PS3 allows you to create multiple accounts from different regions, a lot of people have multiple accounts.
Regulski also promoted the PSN over rival platforms, saying Sony was “the only major console publisher to allow self-publishing”, and continuing:
There are others but they have publishing rules that aren’t much fun and there are no weird limits you have to hit in order for us to pay you.
He also claimed that the PSN offers better royalties than Nintendo and Microsoft, but didn't specify how the rates are different.