The website allmsn.com currently redirects or goes to dating website Ashley Madison located at www.ashleymadison.com, which is legitimate, so I do not think it is a scam. But, some online users have told me that they matched up with people online and after exchanging messages for a few days, they are asked to go to allmsn.com.
Ashley Madison, or The Ashley Madison Agency, is a Canadian online dating service and social networking service marketed to people who are married or in relationships. It was founded in 2002 by Darren J. Morgenstern, with the slogan "Life is short. Have an affair".