What % of winnings reasonable for "backing" someone?

[Spartacus]

It sounds more like you are extending him a further loan, rather than backing him. If he goes broke, he still owes you the amount he loses?

If this is correct, IMO you should not get any of his winnings unless you are 'juicing' him or charging him some kind of interest. As far as the bonus goes, 10% is awfully low and the rakeback should be all yours.

FWIW, I have done similar deals. The player was responsible for the original sum and got all his winnings and 50% of his bonus cleared. Rakeback did not come into play but had it, he would not have seen it. In my case, the player would have played at the particular site anyway, without a bonus, so why not clear mine?