1. When you follow someone on Twitter because they just started to follow you. This is usually done because you want to, but can sometimes be done reluctantly because of guilt or shame.
2. When you and others decide to follow each other on Twitter in an effort to pad the number of followers on each account.
Person A: "John is now following me on Twitter."
Person B: "He's your boss. You should twittereciprocity."
Person A: "Ugh. I don't care what he has to tweet about, but I guess I should."
"Thanks to some twittereciprocity, my friends and I now have 50 followers each."