Adwords - no one is in the coveted 'blue box'

Why?

[rise2it]

I've noticed that for some (many) searches, there are adwords advertisers, but ALL ads are on the right, with NONE in the blue box - actually, there simply is no blue box on the search results page.

What is the trigger for someone to get in the blue box?

Minimum cost?

Minimum CTR?

[jtara]

Nobody knows for sure. It's the blue box black box. :)

One criteria seems to be the number of ads. Generally, if there are a small number of ads, there will not be a blue box. The more ads there are, the more liklihood of a blue box.

I would imagine relevance would have something to do with it as well. If none of the ads are very relevant, they're not going to put any in a blue box.

[dmorison]

AdWordsAdvisor has talked about it a few times - this search brings up a few thread on the subject:

[google.com...]