[tardmrr]

In WoW's Lua, loadstring's ability to load bytecode is deliberately disabled. What you see there is not bytecode. What they've done is put the entire addon into a string and then encrypted it. I didn't bother to look at the specifics of it, but if you really care, you can always hook loadstring and watch what gets passed to it.

Edit: to throw in my opinion, I disapprove of selling addons because I'd rather the author contribute to the community rather than only taking from it. That said, I'm not going to throw a hissy fit and demand that wowi not host the free version.