This offer was also done last month (i received it) and it appears to be rotating through groups of members. There was an offer in July also, but in June everyone could get it. I think US is using this to limit amount sold and see which group responds. I bought it because if US merges with AA and adopts AA mileage purchase policy, you will be limited to a total of 40k miles per year. I figure costs will change if the merger goes through and wanted to be ahead of the mileage curve.