[PaulWaldman]

There are only three reasons: 1. To allow you to charge customers differently for the same product. 2. If you are offering a highly customized product. 3. To establish value for your product prior to providing pricing.

In my experience, #1 is by far the most common for a SaaS.

The rationale of "if you have to ask" falls apart because you could just put a high price on your site to filter out the cheapskates.

I also find that when evaluating a new product, my first click on their site is the pricing page. It is a semi-standardized way to quickly see the significant features offered without all the verbose prose that you'll find on the product pages.