Do you want your blog to be big? Really big? Okay, it's understandable, but as this Marketing Profs post points out, that might not really be the point.
The idea that you need to reach as many people as possible is just wrong. The power of your blog is not just that a lot of people read it; it's that it's relevant to them, and it creates dialog with and among your readers.
Yes, we all want lots of people to read what we write. I claim no superiority here; when our Technorati rank broke through the 1,000,000th mark, I sent a note to Sean and Maureen that said something like "Whoo, we're number 997,246!"
But don't get too obsessed with it. You're better off having a smaller core group of readers who are engaged, interested, and may become new colleagues, customers, business partners, resources, sounding boards, or take on any one of a number of other useful roles. (Even friends!)
Rankings are fun to watch, but don't confuse them for useful measurements of the value of your blog.
One final note: the source of that link above tickles me, because as marketing blogs, go, MarketingProfs is A-List!