For my coming SaaS product (https://www.wisecashhq.com), I created a signup page back in september 2011, then tweeted regularly when I worked on it and mentioned it around (shipping end of september 2012).
It gradually got around 200 "pre-signups", and I used the list to contact people as well and verify my assumptions.
That's what we have done either (but with an Adwords campaign, to see how much traffic there is to be had from Google), but I think that's no commitment to cash, just "I'm interested". I once read here on HN that bootstrappers should actually ask people whether they would pay X$ for that - but now being in this situation, I wonder how to actually do that, knowing none of the future audience in person.
For our product, we know that there is commitment to cash for this category of products, because there are other products in that area which do well as far as we know. What we don't know is whether people pay $X for exactly our product. We have pondered a lot over the free 30x500 course materials, but haven't got around to join the course. We did not spend much on Adwords (< $100) and we did already gather some addresses. But it's hard to estimate the actual conversion rate without asking people to really pay money for it, and without screenshots and the like.
So, yes, we thought we could validate the idea with an Ad campaign, but we did not do it right, I think. We did not measure anything significant at all, and what we did is gather an "I'm interested" list. You are right that perhaps the best ways to validate a product is to ask real people - like asking quite bluntly "Would you pay $30 per month for this product, with this certain USP?", or even "Would you pay me $100 upfront to build this product?". That takes a lot more guts than just setting up a landing page and an adwords campaign, but I see that we should do it.
You are right that perhaps the best ways to validate a product is to ask real people - like asking quite bluntly "Would you pay $30 per month for this product, with this certain USP?", or even "Would you pay me $100 upfront to build this product?".
That's not what I said. Ensuring commitment the way you mentioned doesn't quite work because of divergence between what people say and what people do. The latter is by far the more reliable, agreed?
The 30x500 course teaches advanced 360-degree market study where you learn what people actually do and what they so badly wished they were doing instead. (So yes, you'll learn how to read between the lines, among other things.) The results of that market study forms the most robust foundation to building a value offering that has buy-in baked-in.
p.s. The above is why you'd never hear about the need to "validate a product [idea]" among 3x5ers. The assumptions behind that expression are just wrong to begin with.
Brennan made a signup page, and let people click on the real buy button. That's what he's saying - true validation is when people will pay for it before it's even available.
For my book (see profile) I developed the idea because my posts about cold calling for entrepreneurs became so popular.
After that, I just started collecting emails, asking the list members qualitative questions, and honing copy by testing.
If you started with an idea for a book and no audience demanding it, you should really execute the whole custdev process in one form or another to verify demand. Pre-sales is a great avenue for that.
This is priceless especially considering how much effort goes into writing a book or creating a SaaS product.