Discounted Kindle points to future of ad-supported electronics

Amazon's recent ad-supported Kindle isn't just the future of e-readers. It may also be a look at the future of how people buy electronic gadgets: with a reduced price, subsidized by advertising.

Since April, Amazon has offered an ad-supported version of its Wi-Fi-only Kindle -- "with Special Offers & Sponsored Screensavers" -- for $114, or $25 cheaper than its standard Kindle. More recently, it has added an ad-supported version of its 3G wireless-enabled Kindle for $164, also $25 cheaper than the standard version.