A couple months ago, we wrote on how Google Alerts tweaked their algorithm to be more more quality focused and send out less alerts.

A recent Google Web Search Help thread has more on how Google Alerts works from Google Product Manager, Marcel.

Marcel responded to a quality complaint saying:

I love the end, where he says, “we do send some poor quality documents, either because we’re too quick, and our search engine hasn’t had time to figure out that they are poor quality, or because we don’t get the quality rating right at all.

I just find it interesting to see that come from a Googler.

Forum discussion at Google Web Search Help.