I guess those of us following a “lean” approach to developing software product ideas talk a great deal about how we “validate” them.
The usual wisdom is that you expose your idea — landing page or, better still, your MVP — to the world, preferably in its leanest form possible, perform some sort of marketing activity to draw attention to it (advertising, social media, word-of-mouth), and then measure what the interest is, usually in terms of sign ups and usage versus number of eyeballs. This is intended to give you a very rough idea of the size of the market, and perhaps an informal sense of how much it might take (and cost) to “acquire” each user.
In general terms, I believe this is spot-on. But there is a great deal of idea-specific subtlety that I think you have to gauge each time you do this. I don’t think anyone can distil or teach it and I guess this is where much of the benefit of trying and rejecting ideas comes from. There really is no substitute for actually doing it.
With some (possibly almost all) ideas, validation probably requires that you go out there and somewhat coerce a few people into becoming users of the product. This is what Paul Graham refers to in “Doing Things That Don’t Scale“. It feels unnatural for techies like me, but it’s probably an essential part of the process. There simply is no way to validate the idea itself, until an MVP is built based upon it, and even then passive validation (“It’s here, anyone interested?”) usually isn’t enough to pull anyone out of their busy lives for long enough to take a real look at what you’re offering.
Potential users just don’t often have a gut sense of whether your product is attractive to them, until they’re sat in-front of it, using it… at which point, the lightbulb above their head will either light, or it won’t. Longer-term, they might help to spread the news. But initially, you may have to wire up the light bulb yourself.
Very few products leap straight off the landing page and on to the “sign up” page. And those that do are possibly the result of a process of maturing from a much more manual marketing approach, and no-doubt took many, many iterations to get to the point where they appear to market themselves effortlessly.
I think it’s a balance though between how lean an offering you initially run with, and how hard you push it at people. It really is a question of learning to judge when you’ve exposed or pushed the idea way too little, versus bullying people and trying to magic up a market where none exists. Judging this is quite an art form.