Fanfic Question

When people email me about my fanfic, I generally reply to them but when it comes to Livejournal (and especially Fanfiction.net) comments I don't respond for the most part. I've just read a lengthy discussion on one of the forums I lurk at where some established and pretty well known fanfic writers were saying to not reply to each and every comment they get is ungrateful and downright rude.

Really? I don't think that. I'm not sure what I would reply with anyway. Thank you over and over? I reply when I have something to say back to the person or they ask a question I have an answer to otherwise I just leave it.

Just wondering what other fanfic writers/readers on my friendslist or who read this LJ think about it.