RhinoFish - 3:26 pm on Oct 19, 2011 (gmt 0)

on the other end, we use the AdWords (AW) Placement Targeting Tool (and DoubleClick Ad Planner), and yes, we search by keyword, among other things. in AW, there are sort orders available to us -- alpha by placement (aka domain), volume (imps), relevance, domain relevance...

because i'm an ROI-centric advertiser, i focus on relevance first.

and i see a list of placements that includes sites and also site subsections (channels).

so let's say i was selling halloween candy, and i search for placements, halloween sites are fine, but so are some family or parenting sites, or craft sites. if a parenting site has a halloween channel, i'd rather pick that, than to pick the entire parenting site. but it's up to the site to setup these channels though. and of course, it depends on your content and it's hierarchy and volume. but it most definitely, imo, is in your interest, to think through what portions you may setup as channels - surely doing so will bring you a premium.

here's more for you:
https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=77776
(make sure you see the detailed instructions link at the bottom of this help article)