Not sure if this qualifies as a TOD, certainly a HOD, but here it is:
My wife (no status) traveling on her own reservation, IAH to GRU (UA 979), T Fare. Offered ~ $850 USD to upgrade to BF. Because we were traveling on a tight budget, declined the offer. Offer was seen at UA mobile app.
Surprising thing was, I was traveling on the same flight same date but a different reservation. Identical fare and fare class - no offer to upgrade presented.