I've filled like 5 fills and I'm pleasantly surprised by all the comments so I don't know what you're talking about. Or maybe I'm just used to smaller kinkmemes wherein a lot of fills would get 4 comments if you were lucky.
Op: don't get me wrong, most of my fills have gotten 7-8 comments. But I check each post on flat view a couple of times a day, and I've noticed more fills that have less comments. Really it's only been two or three days, but it's been noticeable, and I feel bad for the authors because in my experience 80% of comments happen in the first day or so (I've done a couple dozen fills, so I'm just going off my own experience.)
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(Anonymous) 2016-02-28 06:14 pm (UTC)(link)no subject
(Anonymous) 2016-02-28 06:28 pm (UTC)(link)no subject
(Anonymous) 2016-02-28 08:43 pm (UTC)(link)