We are setting up a new premium account with Google and the Google sales staff have told us certain search inventory isn't available.
We can see, however, that although someone is occupying a premium spot, that it is an Adwords bidder, because his ad appears on Google's search partners.
I can only see 4 other reasons why the inventory may not be available:
1)Google Amalgamates premium search terms for plurals and keyword order (I wasn't aware of this) 2)The sales staff are in error. 3)There aren't enough searches to justify inventory (no way - this is a main keyword combination). 4) They make so much money on Adwords clicks they don't want to sell the premium listings at the same price as the other keywords we are taking.
I haven't argued the point with the salespeople yet because they are very sensitive and get their nose put out of joint every time I question something more than once.
The way I understand it, it is a first come first serve basis. The first two advertisers to come, can buy up all the inventory for whatever time period they choose. Then there is nothing left for anyone after that until the first advertisers are done with using that spot. It may be the inventory is bought up but that the ads have not gone up yet. Premium ads take longer to get up than adwords.