That's primarily why I don't really deny many requests. Well two reasons, one I think its annoying when the same person tries to add me 2-3 times. Though I understand maybe the second one could be an accident. But unlike the previous version of the site that didn't allow you to add someone after they denied out, my experience with this site hasn't been the same. So, I just don't respond to friend requests if I have no intention on accepting, and I am pretty sure I am not the only person who does that.

...However, people seem to be going the extra mile and taking down their request only to request again, like I hadn't noticed them the first time.