They made an announcement in TUS this morning for a moderately full (100ish) TUS-LAS flight and had one taker. He ended up boarding in the end of the first A group, probably because he didn't realize what to do.
I was talking to the gate agent friend who made the announcement. She told me the first person she had buy up was someone with an A-19 BP on a TUS-SAN flight with 75 people on it. She then had some really choice words about the buy up program.
I heard no announcements to buy up this afternoon at LAS either for my flight or for the flights next to mine.