We've been making revenues for a while at HubSpot (http://www.HubSpot.com http://www.HubSpot.com). Business model is simple: monthly subscription for access to

We've been making revenues for a while at HubSpot (http://www.HubSpot.com http://www.HubSpot.com). Business model is simple: monthly subscription for access to software that meets a need (internet marketing). We've never sold advertising before (though we do have decent traffic on http://grader.com http://grader.com).