I came across this interesting research by Lauren Freedman of the e-tailing Group: The Customer is in Control (note: you do need to sign up to access this but it is free).

This poll of 1300 consumers contains lots of useful information for retailers. The most relevant for us is that 83% of those polled considered keyword search very to most important when buying gifts online. This is yet more evidence that if you’re a retailer you just have to have good search.