Wouldn't the URL be really long and eat up your Twitter characters? You'd be better off running the URL through tinyurl.com or a similar site before posting. I don't think they'd want to be seen endorsing a particular URL conversion site, and leaving the URL long is cumbersome and restrictive. Just my guesses.

TinyURL and the others are industry standards -- and they use 301 redirects which do not affect page rank of SEO. Other retailers (like Finishline) already do this, so it can be done. In fact if you look up at the top of this screen you will see a "share this" button so they are already doing it on MySears -- I just would like to see them expand it to all of Sears.com and Kmart.com

Yeah, I've seen the "e-mail this to a friend" thing on sears.com, but I don't know why they don't do something similar outside of e-mail.