We got the same offer in the mail a few months ago (50K points) no annual fee the first year for small business gold card.

Points already posted and another side benefit is that you can add additional card members and they are automatically entered in membership rewards.

My wife is primary, but I got a card on her account. I used to have membership rewards thru my own Corporate card, but my company stopped paying for it. When I got the Small business gold card, it automatically linked in my corporate card and I am back earning membership rewards points on both.