I’m a big fan of getting feedback rather than the “stealth launch”.
So our new speech therapy web app has been live for 9 months. We’ve advetised in Adwords for 6 months. (We thought we were 2 weeks from “pay version” for 3 months. I guess we were using Jeff Atwood (Stackoverflow) scheduling.
So I"m thinking now that maybe we need to have an actual launch with a bit of PR around an “event” rather than quietly "turning on the “pay” switch.
The launch is announced to some auditory. Do you have a mailing list, professional forums or some other place where the prospects are concentrated and can be reached?
The launch, I believe, follows some period of building up a desire to buy, a “OMG it’s gonna be sooooo good” kind of feeling. Then launch releases that feeling and channels it into the action (of buying). It doesn’t seem you have built that.
I also believe the Big Launch works better for some ground-breaking projects. Adding a new media (web app) doesn’t seem like a launch-worthy event… though of course it may be, for instance, if it allows for radically new features.
I.e. if I were you, I’d channel my efforts into focused marketing to the potential users – patients, their relatives and the speech therapists. LinkedIn? Facebook? Anything that allows for better targeting than blind Google adwords.