This quote from an un-named programmatic specialist at a media company is telling:
If you want our $1 to $2 inventory that’s on the open exchange, we’re glad you are interested in it, but you aren’t going to get much value out of 300 x 250 display ads at the bottom of the site.
In other words, the stuff the doesn’t get sold direct or via PMP is the dreck.
Should you still buy programmatically? Sure, as long as you know what you’re buying and that what you think you’re buying is what you’re actually buying. (These are two very different things.)
But make no mistake about it–the ad tech world is in the business of creating ever-bigger barrels with more gunk at the bottom.