I'm using Twitter as well. Don't update as often as I probably should, but I still manage to get a few updates and popular topics every now and again. I suppose when the bots see 30 some guests on, they probably think that those thirty some people are actually staff members ready to ban on sight or something like that.
Just an FYI when advertising on twitter half of those "guests" are just bots either from Google and or Twitter itself. You didn't get 23 people right off the bat, Unless your like someone of Dr Pepper etc.. They just never registered as a Guest/bot.