I agree with the other commenters that unless I'm actively engaged in the conversation, I won't go back and revisit a blog once I've read it. But if I've commented or asked a question, I will always check to back on the responses.
I will revisit a blog when I've asked a question or made comments on it to see if I get a response and to see what others have said in their comments. I'm always disappointed when an author fails to respond to comments following an interview or guest appearance by them on someone else's blog.
I try to check my favorite blogs once a day, but in case I'm waiting for a reply or follow-up comment I usually don't go back again that day.
Unless the subject is spot on, I don't revisit. But there are exceptions, of course.
I check the ones I contribute to regularly through the day, others not so often.
It really depends on the subject of each blog. I'll return if I need the info again or if I'm interested in a comment thread. If I'm following the blog it is more top of mind.
If I've commented, I'll often go back to read new comments. If I don't comment, I won't usually go back.