If the ads are relevant to the listings, meaning that if the searcher is searching for blue widget books, and the listings in the "directory" category are for blue widget books, and the adsense ads right above the listings are for blue widget books, it benefits the advertiser greatly. They get targeted leads, which is exactly what adwords is for.
Agree. Makes me wonder if adwords advertisers like having their ads on specific-topic content sites (assuming that ads on content sites are cheaper -- are they?).
I'm not talking about scraper sites, but actual content/niche directories (where the webmaster has to manually add their site to be included).
I think scraper sites are OK for advertisers, too and I've read more than one advertiser here on WW say that they're fine with them.