Google gives high weight to blogs. In fact, google gives too much weight to blogs. Too often I've gone to research something that I only know a little about (say, training for a century) and found that my post is on the first page of results. Want to know what it's like to turn 28? I'm apparently the expert.
It does have its uses, however. Today I needed to find an old blog post, and I found that if I type:
eric <word> <word>
more often than not, the first hit is my blog post. Convenient.
Of course, it may be that Google is doing this to protect me from the “Total Perspective Vortex“