I would be interested in hearing opinions about the current inventory of ads and whether WebmasterWorld users believe there has been an exodus of advertisers from Adwords. Have any adwords customers noticed a drop in prices recently?
Media.net confirmed to me that there was a dip in the advertiser demand in my sector, so it's possible that the same applies to adwords.
Obviously, Google can use publishers as a cushion if there has been a decline in advertisers so that publishers bear the brunt of any drop.
If there has been a drop in advertisers, could that have made the whole system more susceptible to "irresponsible campaign parameters, lowering query coverage for specific creative types"?