FTP? From RTR FAQ

Why do I have negative rakeback at Full Tilt?

Full Tilt deduct for a number of things from a player's rake before they calculate rakeback.

1. Bonus
2. Deposit transaction fees (you should not withdraw and re-deposit unnecessarily). These range from 3% upwards.
3. Items bought in the FT store using FT points are deducted at $0.005 per point from your Rake (and $0.00135 from your rakeback).
4. Any tournaments you enter where there is a guaranteed prize and there is a shortfall in players. The amount deducted from your rake is equal to the amount of the overlay divided by the number of entrants.