[gergles]

> you're playing with house money including the bonus

No, you are never doing this. The prices should just be 5% cheaper and there should be no 'bonus'. The fare is obviously set taking the bonus into account, so it makes more sense to just drop the prices and to drop the bonus.

[dfxm12]

There's more to it than that. MTA is competing with, for example the port authority's SmartLink cards when it comes to paying fares for the PATH trains. That 5% bonus is also a carrot to get people to get the metrocard.

...and MTA doesn't set PATH fares.