Mayday alerts about problems across all browsers and tells you why [Springboard]
So MaydayHQ is out to alert companies when users have problems with a site, and tell them why.
Yes, the monitoring space is very busy. But Mayday is very focused on technical and developers. Gosquared is more focused on marketing. IMayday is about performance, javascript errors, server problems etc
The Business model is a monthly subscription, the more you use the more you pay. They are in Alpha right now, but launch in a couple of months.
Mayday is founded by Ben Hall and James Hollingworth. Ben is the author of the book Testing ASP.net Web Applications. James previously worked at Huddle and Toptable