Is it bad for SEO purposes?

Hi,

I installed Pay With a Like 2 months ago, because I thought that all the likes and shares in the social network, would benefit my overall SEO.

But I've found the opposite. Here's an screnshot of the stats for my best post: https://img.skitch.com/20120806-dy3ke5anpudsqxnnb2u7ind88r.jpg This post has received more than 700 facebook likes in this 2 months...but it seems that Google didn't like them...

It was clearly a post that was growing in traffic but, one week after installing the plugin, it started to decrease the traffic. And the same for the overall site. I haven't changed anything else, and the "effect" start just after a week after installing the plugin. This

Anyone else is facing the same? Any ideas?

Thanks.