Is it this offer:
Earn 100,000 Membership Rewards® points after you spend $5,000 on purchases with your new Card in your first 6 months.† Plus, earn 10x points on eligible purchases at U.S. Gas Stations and U.S. Supermarkets with your new Card in the first 6 months, on up to $15k in combined purchases.
Because if it is, that's a pretty good offer and I'd say, it'd be hard to turn it down. The easiest way to use MRs is to later get a Schwab Platinum Card and cash them out at 1.25cpp. There are also travel uses & transfer partners which get varying rates (some better than 1.25), and gift cards (at 1cpp). I'd google it and read some of the blogs on all the uses to get a sense for how YOU might use them because unlike some of the other currencies, the uses for MRs are very scattered.