Not optional: the serial comma

If you’re not sure what the serial comma is, check Grammar Girl’s post about it. I agree with most of the points she makes, but feel strongly that it shouldn’t be optional. Sounds like the only reason people started omitting it was to save space in newspapers. Understandable in that situation, I suppose, but otherwise I think it’s a necessity because a) it removes confusion from sentences like “My favorite sandwiches are hummus, turkey and avocado and ham and cheese.” and b) it prevents ridiculous sentences like “My favorite sandwiches are cheese, ham and ham and cheese.” (Not sure why all my sentences are about sandwiches.)

Also, I see a lot of publications and websites (mostly websites, in fact) that use it intermittently. The inconsistency can be distracting. Since the serial comma is necessary sometimes to avoid confusion, and inconsistency is problematic, I vote everyone uses it all the time. Just my opinion.