Bonus playthrough explained please

Can someone please explain what the highlighted portion actually means???

Hello,

I can only read the description below to give you a hint. Could you please specify which sweepstake casino you are referring to? I believe the support team should advise, and the rules should also help. Yet from my own experiences, sometimes none of those options brings results....

It is a wagering process, very likely associated with the rank; all the categories are mentioned, and SC coins have a special multiplier. The casino offers more than one currency, and sweepstakes coins are "harder to wager." Hence comes the percentage to help you track the progress.

I could really use the specific terms here. 😀