Let the hive mind of Engadget get that for you.
"I'm looking for a pair of quality headphones that aren't seemingly made of glass. I'm an avid BMXer which causes me to frequently bash on any type of technology that joins me for my daily riding. I've been through the higher quality headsets in the Skullcandy line as these are supposed to be built for "abuse," which is laughable. I cant wear earbuds or canal buds, as my large ears seem to have a repelling property upon anything that sits in them. Wired or Bluetooth doesn't really matter, but I need something that can hold up to taking a few hits every now and again. I'm trying to keep 'em under $150. Thanks!"
It's not an uncommon practice to bundle in "extras" to encourage growth in a market segment. During the push to DVD by the industry, Mission To Mars (and several other films) came in bundles where you got a DVD version of the same movie for free. Dragon Age: Origins comes with download-codes for extra content to get people into the habit of going online to look for that kind of stuff. Why SHOULDN'T they bundle books with a download code? It's extremely cheap advertising that bolsters their online efforts.