Sorry if you've said something profound and interesting that I haven't replied to; it's not that I'm ignoring you, it's rather that I probably haven't realised that your comment exists.
Lately, I've noticed a sharp uptick in the number of comments that are just more or less thinly disguised spam, so I've been going through and marking all the offenders. It's a pain, but perhaps if I remember that I have to do that, it might encourage me to remember to read (and reply to) the proper comments more regularly as well.