Exactly this. I run the same validation process for almost every product idea that crosses my desk. A simple landing page, a waitlist form, and a modest ad spend - usually £100-150 on LinkedIn or Meta depending on the audience - is the cheapest way to gauge intent before writing a single line of backend code.
What a lot of people miss is the threshold you set for "good amount". I have a rule of thumb: if the cost per waitlist signup is under £2 and I hit 50+ signups within two weeks, that's a green light. Below that, I dig into the source - maybe the ad creative is garbage, or the targeting is off. One script I always bake into the landing page is a simple event tracker that fires on form submission and pushes a custom property into the CRM. I use this snippet:
document.getElementById('waitlist-form').addEventListener('submit', function() {
window._paq.push(['trackEvent', 'Waitlist', 'Signup', 'Idea-Name']);
});
Lets you correlate signups with ad channels and organic traffic without needing a full analytics stack. If the organic conversion rate is under 1 % after a week of zero ad spend, I'd probably kill the idea. Paid can mask poor product-market fit, so I always let organic runs sit for a few days first. It's messy, but it beats building a full MVP that nobody wants.
