[piotrkaminski]

So answering myself, with numbers pulled from https://expandedramblings.com:

GitHub: 31M users

BitBucket: 6M users, 1M orgs

GitLab: 100K orgs

The GitLab number tallies with Emily's answer, which gives me some moderate confidence that these numbers are in the right neighborhood. I'm also going to assume that the users-vs-teams numbers are all in roughly the same proportion.

Based one these numbers it doesn't make much sense to target BitBucket unless either 1) they're growing much faster than GitHub (unlikely) or 2) their customers are a much better fit for Reviewable (possible, but it would have to be a truly significant difference in userbase composition). Targeting GitLab doesn't appear to make sense at all (as a business), though perhaps they're growing fast.

[xorgar831]

I'd go off of the BitBucket plugin install counts and compare them to what you're getting on GH:

https://marketplace.atlassian.com/addons/app/bitbucket/top-s...

[piotrkaminski]

It's hard to compare, since Reviewable is an OAuth app and hence needs an install per-user rather than per-org. However, on the page you linked I see a couple apps topping out at 6-7k installs, and most of the rest are in the low hundreds. This doesn't look particularly impressive to me...