Well this is more interesting - I am a Plat. and today I did receive my card with this offer but it reads:

25-29 = 10,000 bonus
30+ - 20,000 bonus


I can only assume that Starwood is pushing everyone for more stays than "normal" historical stay rate.

My office pal with lower bonuses is a gold - this is in reference to the above post of the offer she received.