You say "the solution ...". I think there are others.
Like have a default maximum spend in Facebook of $5 per app and $50 total, and require at least a double-lock to enable a higher level of payments.
Double lock: user confirms by ticking a box and by following a link in an email, say; then they get a message on their Facebook saying "you authorised higher spending for $game, up to $amount".
They could require pre-deposit, not allow use of credit cards, only allow spending if your credit rating is good, etc.. But none of this things increase mindless spending.
Like have a default maximum spend in Facebook of $5 per app and $50 total, and require at least a double-lock to enable a higher level of payments.
Double lock: user confirms by ticking a box and by following a link in an email, say; then they get a message on their Facebook saying "you authorised higher spending for $game, up to $amount".
They could require pre-deposit, not allow use of credit cards, only allow spending if your credit rating is good, etc.. But none of this things increase mindless spending.