Can you start a new campaign and only choose the "content" (adsense) network to run?
or do you have to get through an approval / minimum number of impressions on the regular google search network to be seen?
howiejs, since no one has picked this one up yet, I thought I'd chime in.
All ads will show on Google, and then, also, on partner sites once reviewed/approved.
But there is really not a way to show on the Content partner network without also showing on Google - which is what you're asking about, if I've understood you correctly.
And just to be clear, there isn't a minimum number of impressions you must have on Google before going to partner sites. It is simply that the ads & keywords must be reviewed and approved.
And once ads have gone to partner sites, they continue to show on Google as well.
AWA