Ask HN: Is your business a company or a product?

When I read the stories on HN of people promoting their new product, I see many people starting businesses whose names are the same as the product they're selling. This is different than some traditional notions of companies where their name is different from their product, and they have diversified into one or more product categories.

My feeling is that if the company's name is different than the product that they're selling, the company can create any number of potential products without having to reincorporate or shut down operations (under the previous business name).

There no 'one right way' of doing it, but is there an advantage (revenue, tax, buy out, etc) between having a company whose name is the same as their product (e.g. MobileWorks), or one whose name is different from their product (e.g.: 37Signals)? If there's no advantage, why do people name their company after their product?