Recently I've had a spate of comments making innocuous but generic and not terribly relevant remarks, from people with names or web sites pointing to stock promoters, Viagra sales, and so forth. I've been deleting these as spam.
If you are a real person and your comment has been deleted in this way, I apologize. Make a substantive comment under an actual human name (ideally, but not necessarily, your own), and point to a link that is even remotely relevant, and your comment will get through. Behave like a spammer, and be treated like one.