Gmail has a 100-comment limit per thread. So when we’re getting close to that number of comments, we start a continuation thread which references back to the original thread.
If you’re a client, this is a good thing, since it means we’ve gone through a lot of communication and iteration cycles to tune your campaigns.
Rather than wait to 100 comments in a thread, we’ll start a new one at around 80, since we don’t want to hit that limit, which would kill our ability to track and follow-up. Our team members use the Boomerang by Gmail app to track follow-ups, so sometimes you’ll see us start a continuation thread at only 50 comments, since there might be a few dozen internal follow-ups that you don’t see.
We allow any team member to start a continuation thread if they see the thread count start to get high– it’s not like fine sheets, where you want a really high thread count!
If you want a peek at how large-scale project management is done, you might be amused to know we have some threads that have 7 continuations on them, meaning that we have 700 iterations on that one thing. This is the case for our Team Roster, which we update every couple days, as well as some of our core courses– Dollar a Day, Social Amplification Engine, and so forth.