Consider the alternative. Say the opposite. That your condo isn't right for everyone. That your software might be overpriced. That this new model car is in fact quite difficult to use.
And then tell us why. We'd love to know how you're going to wriggle out of that. And along the way, if your story is a good one, we might even give it a try.
This goes beyond just writing your ad-copy. This is very valuable in real life documents, hell, even email for persuasion.
There are many things that a good PM can get trained on. But, nothing beats effective communication skills - specifically pithy persuasive writing that best explains your "gut" feeling.