I was always a huge fan of Gmail and pretty much used it for everything. But, over time I subscribed to various site newsletters. And, in the end my inbox was over run with spam. And, no matter how many times I clicked the spam button, the emails still came in.
One of the biggest reasons I stopped using my Gmail so actively was due to the massive volumes of spam emails or emails from sites that I was no longer interested in.
More recently, I have tried to clean up that Gmail box and get it into workable shape. I think there are many good benefits to using Gmail. But, right now, it feels completely disassociated with all the other services I am using.