I ran across their URL from one of their client sites. They seem to have a script to pull up some sales saving devices to entice the customer back to the client website or to serve up an exit questionaire. I have not allowed the scrips to run, so I do not know how effective it is.
From their website:
UpSellit is a powerful eCommerce and lead generation solution that allows marketers to automatically interact with abandoning consumers in order to gather customer feedback and increase conversions. Turn abandoning consumers into buyers with an engaging and responsive automated chat, email remarketing or abandonment survey campaign.
We at ***** are simply providers of A.I. based chat agents for customer support and sales. It is perfectly compliant flash/javascript code with NO downloads -- it is simply not MalWare.