Almost all my traffic comes from searches for "<coursecode> textbook", and heads to individual pages that look like http://textbookcentral.com.au/26/university

Almost all my traffic comes from searches for "<coursecode> textbook", and heads to individual pages that look like http://textbookcentral.com.au/26/university-of-new-south-wales/buy/69897/acct1501/?query= http://textbookcentral.com.au/26/university-of-new-south-wal... That doesn't look like an individual page but it actually is; there's a unique link for every dialog. I'll definitely follow your advice and test some ads on small number of pages and see how that goes first.