What impression do you want to make?
Dean Shareski is an Educational Technologist in Saskatchewan. He made a list called The Best of the Blogosphere for New Bloggers. You're on it. More than that, he suggests that you guys are THE example of how math students can also be bloggers.
A new teacher blogger writes about you and mentions Sarah's blog in particular to demonstrate to her students how they can benefit from blogging.
On October 17, 2005, an online news article entitled Blogging 101--Web logs go to school mentions you on the second page as the only example of how blogs are being used in mathematics.
You are the number 2 hit when someone uses Google's Blogsearch to look up calculus.
You've already made an impression.
Now what are you going to do, not just to maintain it, but move it up to the next level?