So people have to be buying it now either for the 20% interest or for some current use case.

And the only other currency use case that stands out to me is putting it in the liquidity pool as pHBD.

There might be a few other apps using it as payment that I am not aware of. However, the options are rather limited at the moment.

Nevertheless, the 20% APR is a pretty good starting use case. Happy how things are unfolding so far.