When testing accounts for automation, a metric @ZellaQuixote and I have been using is whether the accounts A) post 24/7 and/or B) post 90% or more of their tweets via automation apps/services. We decided to apply this test to our own followers.
Of 32045 accounts that follow one or both of us, 232 tested positive for automation per this test. This chart shows the 25 most common apps/services used to post the tweets. IFTTT and Buffer are the most prominent. 
Here are the hashtags most often used by the 232 likely bots following @ZellaQuixote and/or myself. Many are political, but there are also some that seem promotional (#Yelp). #FollowTheWhiteRabbit is a false positive due to two bots we created, @BakedAlpacas and @SeanSpammity.
What do the probable bots following us tweet about? 23.2% of their tweets contain one or more of the following terms. Trump is a big theme.
Here are the websites most frequently linked by the bots in question. Some of the non-news sites seem shady: there's aiobot(dot)com, a site which charges $325 to automate purchases of newly released shoes, and two dating/hookup sites - datememe(dot)com and altleft(dot)host.
Much appreciation to @ZellaQuixote for assistance with this thread (as well as sharing the role of subject).
