What I think is it is very essential that you read others blog posts and leave insightful comments. Some people leave generic comments on every post. I never prefer someone to do that. Write meaningful comments. When you read others posts, you get many ideas and you also get familiar with different writing styles. Its also a very good learning and evolving method. Success in blogging comes only by developing a good network with fellow writers. Interaction is the key to success in blogging.
Those generic comments are written because they think that this is going to be a promotion to their "name/brand".
However, this works the other way. If someone writes something meaningful it will get more respected and will show that he is knowledgeable - leading to a better network.