...but the price is not. They have no serious competitors as far as I can tell, the market is screaming for competition. If you need to build a network-accessible database driven application that runs in a browser, it's really, really slick.
I was involved with a project to build a type of customer database using QuckBase - it would track and follow a customer's project all the way to completion, and multiple people with different roles could interact with it in various ways. Imagine Filemaker Pro or MS Access on steroids and network enabled.
To earn our business, QBase reps basically built the bones of the program in realtime as we chatted on the phone and watched via webex, for free and gave us a month to play with it at no cost. After that it was around $300 per month, so out of range of individuals but fine for businesses that can justify it with revenue.
I think there is a huge future for this market that's waiting to be tapped further. Right now it's a bit of a monopoly.