The guidelines do say "no site is guaranteed a listing."
What it takes is: provide enough unique content. Make the unique content obvious. There is very very seldom anything else involved.
The definition of "unique" is pretty simple, with one point that is better understood by the general public than the marketroid dens, and one wrinkle that is vaguely alluded to and strongly emphasized (interesting rhetorical trick, that!) in the submittal guidelines.
(1) There is no such thing as unique advertising, promotion, marketing copywriting, etc. All that can be unique is actual information about the product offered. No unique product or service == no unique content. Most of the world understands this, but marketers understandably don't appreciate it, which is fine with us. Another way to say this is: content is information, not persuasion.
(2) An entity is assumed to have one website on a "topic", with the definition of "topic" very broad in "Shopping" and narrow in, say, Arts/Literature/Authors. Our assumption is that all of the entity's content is linked together, and we'll post one link to it all. This surprises some web marketers, but it is a very very important point for us. (So even if you presented all unique content on site A, and different unique content on site B, we'd only list one of them.) This is easy enough for people to deal with: one umbrella sites pointing to all the other sites, and all the others linking back to the umbrella. We would consider listing the umbrella.
[Caveat: I haven't looked at the site recently if at all, so these are genuine generalities. All or none may be applicable to any particular rejected site.]
One final point: there is basically never (well, hardly ever) anything to be done about a rejection. This follows pretty directly from our definition of "unique content." Another way of looking at it is: the site serves your purpose, OK: it doesn't serve ours, so ours doesn't list to it, OK. There's room for more than two purposes on the web, and you're welcome to all of it that's devoted to your purpose.
