Yeah I'm planning to cover a bunch more sites like twitter, Reddit, imgur, etc. Time waster sites. But I'm def worried about how all these sites are adopting frameworks, cuz it makes the DOM more dynamic. I think the number of sites the plugin can cover will be a function of popularity and contributors.
Thanks for the data, if I estimate 1 breakage per site per year (plan for the worst) that helps me get a picture of what I think I can support myself