There are stories and authors on one site or the other. Not all the authors on SOL post on FS. So its natural to have stories and authors there who don't show up on SOL.
Exactly! Also, there may be more than one author (other than myself) who favor FS by posting chapters of a serial first on FS and lagging somewhat behind on SOL.
Really, there's no reason for someone NOT to check postings on both sites. Considering that a few of us wish to point family & friends to our work, and don't want to point them to an obvious erotica-oriented site like SOL, it's plain that we'll point them to FS. My only fear is that lack of activity there might lead to FS's demise, hence my attitude of favoring that site.
FWIW, I've got a good friend posting there, now, and I'm pleased to see his serial increasing its score points in recent days. Lot's of hard work involved there, but worth it.