One of the simplest ways to increase click through rates on "featured" or "recommended" products from your home page or email campaigns is to give customers a clue as to why the items are featured.
Compare a merchandising zone like this:
To these:
Crutchfield recommends 3 iPods, and customer chooses which is most attractive - the best deal for the price, the top rated item or the expert/staff choice.
L.L. Bean's emails consistently feature products backed up by some outstanding attribute that justifies its recommendation. Value propositions, baby.