[kyriakos]

Although I agree with your points, there is something about this that bothers me every time I start on a project and think of making a landing page. My concern is, what if I take too long to launch from the day the landing page goes online? Won't that mean I lose any of the potential customers that found my product idea interesting in the first place?

[benediktdeicke]

Even if you don't convert anyone from the mailing list, you're still better off than without it. You know that there is interest in your product and that there will be more people looking for a solution like yours. It's very unlikely that all potential customers ever will sign up to your mailing list long before your launch.