I say it depends on the below few factors :
2) subscriber count
If you want to know if a blog is good or not, try to spy around for their comments from past months and check the numbers for current months. I normally only subscribe to a blog when I am sure that those are people from the same community. I.e. whether they are humans with their own blogs.
If you see a blog that goes on for several months and weeks without a single comment, there must be something fishy there.
I have caught some lame ass faking his own subscriber count and that left a WTF feeling in you. I won’t be impressed with those that have thousands of subscribers because normally by the time they reached that number, they are probably ‘used’. There is nothing exciting from their posts anymore. Over-rated.
I have several SEO consultant blogs in my feeds and I really like their contents as they are fresh, based on their own experiment and nothing pretentious.
Having said that, I am sure other people use different factors to gauge a blog’s quality before they decide to subscribe. What are yours?