[sjtgraham]

Essentially, no one but you cares that "it's green on my box". Your clone is not the "source of truth".

Also not everyone runs tests before pushing, shocking I know! CI SCM integration makes it immediately clear if a branch can be safely merged. This is such a win for open source projects too. Often I'll get a PR, after seeing the diff and the green build I know I can safely merge. Compare this with adding the contributor's fork as a remote, fetching their changes, running the test suite, merging, pushing. I know which one I prefer.

I'm even more excited about CD, there should be a process for deploying to production and I'm not talking about `git push heroku master`. Code deployed to production should be code reviewed and built by CI before it is automatically deployed. IMO this significantly reduces the probability of deploying bad code.