Many things but it has to be converted by the third-party service that online shop I used to shop with. But I guess the main and important thing is to pay bitcoin with every purchase right? So it doesn't matter if they convert it to fiat automatically upon purchase as long as the transaction goes through. IIRC, most purchases that I make with bitcoin weren't that expensive, they usually go around converted in fiat from $10-$100 and those things that I shop online are only the necessary things. It's convenient since it's allowed by the shop that I usually go to online and I'll just have to wait within a few days and the package will arrive.  
Yeah, the quantity may be a lot before the bull run but that's the purpose of bitcoin, it's for paying stuff so don't forget to treat yourself while holding a lot.