Chase is offering the United Visa free the first year with a 20,000 mile signup bonus and an additional 5000 bonus miles when you fly a paid United roundtrip by March 15.
Certainly the first purchase bonus will post for everyone, and the fee will be waived for anyone using the link. The 5000 mile bonus for a paid roundtrip is something of a question mark — since the fine print of the offer indicates a United promotion code (MPGJ15) it may be only for members whose Mileage Plus accounts have been pre-registered. So your mileage may vary on this piece.
(Hat tip to Don.)