[apsurd]

Most shopping carts are abandoned because the buyer just wanted to see how much a purchase actually costs. Factoring in shipping, taxes, and possibly shadily hidden fees.

  "All set to go with your purchase Mr. Smith?"
  "Nah, I was just testing ... =) [close tab]"

[datasink]

The fact they went through that exercise demonstrates that there is some interest, however. With retention systems, you have the opportunity to save a sale with a time-limited coupon code, for those that may be bouncing because of the price or because they wish to return later (which likely won't happen). For certain types of products, this is really effective.