...i managed to get an offer for the first time. and its good...too easy?
Spend 100, get 2400 miles. Spend 350, get 9900...
I wish I had seen this before booking my older trips. But That's pretty much 10k bonus miles for a roundtrip flight.
It's base fare only (not surprising), and has to be UA or UAx flights (also not surprising); basic economy does not count (mildly surprising).