Do they help the player writing them?
I can't speak for everyone, of course, but it helps me because:
- It's a good way to keep track of my goals and progress.
- It helps unclutter my mind. Ranting about the occasional bad beat or (more often than not, in my case) stupid play helps get it off your chest and refocus for your next session. I usually save the questionable hands for the hand evaluation forums.
- It keeps things in perspective. For example, I keep a record of my current bankroll on mine. I've been stuck at around $400 lately, which has been really frustrating. Looking back a few entries, I realized that just a few weeks ago I was having troubles hitting $300 and wondering if I could even get to $400. So, it gave me a good shot of confidence.
Do they help the players reading them?
It depends on the person and the blog, but I think they do. You can get a look into another player's mindset and perhaps see things from a different perspective, or come across things that you may not have realized or experienced yet. Plus, if you're just starting out, it's nice to know that you're not the only one going through growing pains.
Do they just entertain?
Mine probably doesn't.
There are some very good ones out there, though.