S.P.A.M. - Shop small Chicago Amex $10 cash back

http://shopsmallnow.com/chi
Amex is giving $10 back for shopping in small businesses in Chicago area.
Got the invitation while sitting in the park

The question is can I register multiple cards under the same account an d is it valid in Chicago only or all over the country.

What if I have the same offer in Boston? Will it qualify for an additional cash back ?

This website indicates that the offer is valid in Boston, Chicago, and Philadelphia (until July 4, 2012):

http://www.hustlermoneyblog.com/american-express-shop-small-free-10-statement-credit-for-boston-chicago-or-philadelphia/

Here are the official Amex sites:

https://shopsmall.americanexpress.com/

www.shopsmallnow.com

It appears that if you are not in Boston, Chicago, or Philadelphia, you need to wait until Nov. 24, 2012, which is the next Shop Small Saturday. (This promotion also took place last November, and it worked quite nicely!)

http://shopsmallnow.com/chi
Amex is giving $10 back for shopping in small businesses in Chicago area.
Got the invitation while sitting in the park

The question is can I register multiple cards under the same account an d is it valid in Chicago only or all over the country.

For the national Small Business Saturdays I've registered (among others) two AmEx cards that have different numbers but are tied to the same account. One is in my name, one is in my wife's name. We've successfully used both of them two years in a row, buying gift cards at our favorite local restaurant.