What with Oprah Winfrey’s ability to sell books well established, can there be any doubt that her endorsement of Kindle, Amazon’s e-reader, will have an enormous impact on the device’s popularity?

We’ll just have to wait and see.

In the meantime, Amazon.com is offering Oprah’s viewers $50 off the price of Kindle — just enter the promotional code OPRAHWINFREY during the checkout process at Amazon.com to receive the discount. This offer is valid through November 1, 2008.

(Don’t tell anyone we said so, but you actually don’t have to be an Oprah viewer to take advantage of this offer.)