If you actually run a good restaurant ( not subjectively good, but objectively good ) then you can tell Yelp to take a hike every time their sales person calls so it would never be surfaced more than some taco place which for some reason did decide to give Yelp money. I'm sure this affects placement, not to mention probably frequency of reviews/checkins plays into placement.

It is not that Aska NYC gives two cents about it not showing up on every Yelp search - after all they are a place that gets away with charging your credit card when you make a reservation and offers no refunds!