User blog comment:Hihi-sama/I don't care about the ratings./@comment-3174012-20110914002807

Here's a more probable reason to why it probably didn't get as many viewers (neither will the rest of the arch).

The reason to why iDSF didn't get as many viewers is because it wasn't as "exclusive." The other iCarly episodes in other seasons got more viewers because it was spread out and it was rare to see it. But now, (so far) we're getting episodes each week and is predictable. Think about it, would a normal person be more inclined to watch icarly if he knew it was every week or if it was only once every other month. Truly, he would pick the latter since the episodes are more "rare," and thus, "exclusive." This arch will not be as rare as other iCarly episodes in the past season. Don't expect to get outrageously high viewers for this arch.

Sorry if that's hard to understand...