Amazon
Prime gives you access to unlimited free two-day shipping on many items, plus access to thousands of streaming movies and TV shows through Amazon Instant Video, a service similar to Netflix. There have also been reports that Prime members will soon get access to a Spotify-like streaming music service.
Amazon's site currently encourages you to sign up for Prime at the old $79 price for another seven days. You can sign up now to lock in.
The price increase shouldn't come as a surprise. Earlier this year, Amazon said it may raise the Prime subscription as much as $40.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.