Used to LOVE this plugin. Now all of my readers have to install IE or FireFox plugins to use it.
1- never ever ask your readers to install something to make their time on your site better. (remember the '90s, when developers would offer you a font to download before entering their site-- remember how LAME that was then?) There are plenty of other WP plugins that can get the social network sharing job done, and they all do it server side.
2- without the browser plugins, it isn't even clear what is supposed to be happening, so even if I did want to demand people install things on their own machines to view my site- there isn't anything explaining WHY.
I rarely if ever give star reviews to plugins. And even more rare is me writing something. But I logged in just to give a 1-star (since 0 is a no vote) and to tell everyone why.