When they claim they got 100,000 email signups in a week (and make it look as easy as microwaving popcorn) — they’re playing you.
Very well said sir.
Building a mailing list with real people interested in whatever half-baked thing you promise to put out, and clicking on your emails when you send them, and talks to you about what is working and what isn't - that takes sweat and blood. It also takes a lot of unsubscribes to weed out people who're attracted to the new and shiny, but are not the audience to whom your business would provide value to.
You may have heard some “lean startup” gurus running around telling you to create a page that looks exactly like a finished marketing site, complete with screenshots, etc. and that you should “trick” people into signing up for your service to test if they’d pay for the finished product.
That's it. Bookmarked, recommended, and followed. Please keep writing.