[thirdsun]

It's not, unless by all you mean some digital content. Donation-based content is still the exception and I think it's fine for creators to set a definitive price/value for their work as they see fit.

I buy my music digitally, lossless for a one-time flat fee and I own the content, ready to played with any player/software I can think of. With software and games it's slightly different since there's usually DRM involved, yet there's rarely a tip jar to be seen.