If you read what they said about the sales it would tell you that they will end January 9th. Yes i agree this is a long time, But you gotta let these guys have some time off for Christmas.
Not hard to plan ahead of time and automate sales.
They have a community that's constantly asking for items like give us X on sale, give us Y on sale, it's not hard to throw a few sales together when that's exactly what your job is sales.
We have a "sales team", and I wouldn't be surprised if they had to get approval a few weeks in advance for every sale, but it seems really like a bad effort on their part (there were daily sales up, but hell they were random and for 3 days it was Superior Experience Charm to Superior Talent Charm to Superior Experience Charm; not quite sure what they were thinking with that one).
Even if they broke up their main sale into 3 weeks; it'd have been better to create some diversity, people in this game look forward to sales, and it just seems like a stupid idea to have the same sale for 3 weeks straight.