We're With the BandThe 2011 Engagement & Jewelry Survey from The Knot Market Intelligence and the XO Group Inc. looks at couples' buying behaviors for wedding bands. JCK highlights some key areas where retailers can profit.Twenty-six percent of brides opt for custom looks, compared with 16 percent of grooms. Custom departments are booming—retailers returning to their roots as craftsmen couldn't agree more.Thirty-six percent of couples buy bands at separate retailers; 10 percent buy at least one band online (usually the guy's). Wedding band weekends are a phenomenal way for retailers like Massachusetts' Long's Jewelers to get couples to commit to purchases together. There's a larger selection, designers themselves are often present, and the events foster closeness and teamwork.Only 22 percent of couples buy the bride's band as a set with the engagement ring. Retailers need to do a b