[mluiten]

I actually like to add an intermediary step between the landing page and the e-mail form: a "Create an account/Buy now for $X/month/year" button. When people click on it, they get a "Sorry, we're not done yet, but give us your email and you will be notified once we release" + the email form.

Not only do you know people are potentially willing to pay X dollars for your product, you can also do a multivariate test on different amounts or pricing schemes to see if they convert differently, giving you some rough idea how much your idea is worth to them. I always add a "Make an account for FREE" as well, as a baseline.

[dberube]

Well, the problem with doing that at this stage of the process is you risk getting the initial price completely wrong and nobody clicks it.

Even though, if you had priced it just $20 lower, everyone would have clicked it.

So by putting price in the mix before you even identify a willing market, you risk missing the ball completely.

[mdda]

You could put up a separate pricing page to see how many people click through to it, and then look at hovers to see where they linger... But that's obviously going a bit deeper than the original idea of slapping up a single page to gauge interest.

[cbr]

You could A/B on price to get the demand curve.

[dberube]

But you still leave open the possibility of not learning the basics of whether or not someone wants the problem solved.

[tagawa]

It's probably just me, but I can't help feeling it's a bit underhand to offer something for sale that doesn't exist yet (unless you make it clear upfront).