Some blogs ask their readers for money to help operate the blog. That's quite understandable, but we fortunately don't need that -- the real cost of running the blog is time, and that's generously subsidized by various universities and state taxpayers.
We're in it for the eyeballs. (Yumm, eyeballs.) So if you like the blog, just let your friends know about it -- perhaps take a blog post you really like, pass it along (together with its URL) to people who you think would enjoy it, and tell them that there's a lot more where that came from. Or not: We're happy with just your eyeballs, too.