Ask HN: Wordpress premium themes business

For my limited experiences, premium theme business seems a quite profitable and attractive.

Although from some comments from HN, the profit for this business is declining now. (tasty theme and wpreviewsite plugin), personally I still think it is the way to go.

But anyone in here had experience about promoting,marketing and making sales about premium themes/plugins?

Correct me if I was wrong, in general, these premium themes do seem hard to code, some plugins, for example, gravity forms, takes time to build but still, not the rocket science. so i guess the problem is down to how to promote, marketing, and sell these theme/plugins, any ideas suggestions?

Cheers,