party poker bad beat rake (puzzle)

[Paul2432]

Party Poker advertises their bad beat distribution as 70% to the table (with the most to the player badly beaten), 20% to seed the next jackpot, and 10% withheld as Party's fee.

In fact, in the long run party will rake more than 10% of the money taken in by the bad beat rake. Why is this and what is the true long run percentage?

I'll post the solution in a few days if no one comes up with an answer.

Paul