Obviously, there are no hard and fast rules that apply here and that just about everywhere, you’ll find exceptions to any simplistic generalization I’ll post here or you read elsewhere. Still, understand that my information is mined from years of communications with fellow bloggers of all political stripes (or completely stripe-less) and professional experience with online media that dates back to before most of you ever knew the Internet exists. Data here also comes from general publishing and marketing studies, and from statistics and anecdotal evidence compiled by others I respect and/or have a good track record of accuracy including professional news services.
[Feel free to share your own observations/comments, etc. here (as a left-leaner, I'm not just statistically more likely to invite feedback, I actually encourage it).]