In my experience requiring either of the two options below dramatically reduces spam accounts.
- Sign up and sign in using OAuth
- Email Verification if not authenticated through OAuth
Pretty neat, maybe you could consider a programmatic CLI API to add and remove domains.
Check out hose for an approximation of what I mean
https://github.com/bevacqua/hose
It doesn't just apply to writing Gulpfiles, but also to extending the functionality. Extending functionality in Grunt is much more straightforward in the sense that you just write a function.
With Gulp, you need to know your stuff in order to write a reasonable task, and the fact that Gulp tasks run asynchronously by default can get tricky, too.