If you have questions about using mojoPortal, you can post them here.
You may want to first review our site administration documentation to see if your question is answered there.
I'm just trying out the AddThis widget as described here and thought it worth mentioning that as well as the AddThis username, you can enter your Profile ID instead.
AddThis profiles allow one AddThis account to manage multiple domains and give clients/partners access to analytics data for their domain without logging in to the owning account, and various other things. More info here.