Not sure you can reliably measure the size of a business based on its social media engagement, nor Stumble Upon "views" for that matter. Some of the fastest growing companies (based on things like, you know, revenue, profit etc) are enterprise businesses which inherently have less social interaction than a recipe or deal sharing site.<p>Also, no offence intended to Guy (the creator), but is it a coincidence that his Lifx startup is #1, and that that is heavily due to the StumpleUpon views which have jumped massively in the last week? Looks a little too convenient to me ;)