The Twitter barrage

In the last forty-eight hours I have acquired many hundreds of new Twitter followers for my Twitter posts, yet for no apparent reason.  I've probably doubled my number of followers over the last two days and that includes a concentrated swarm of followers with Russian or Ukrainian names (what about Belarus?).  Today I can click on my email every few minutes and have a bunch of new followers.

Yet I have done nothing notable over that same time period nor have I received significant media coverage.  What accounts for this equilibrium?  What is the underlying model of social contagion?  One model is simply that these followers have been queued for weeks by Twitter and the notices are being released only now; does that accord with your experience as a Twitter user?