That could be a powerful offering if Amazon can boost the library a bit. $89 per year for Amazon Prime with 2 day shipping and streaming is a few bucks cheaper than a year of Netflix streaming only (7.99*12=95.88) and potentially much more valuable.

For someone who shops at Amazon a lot, only uses streaming a little and doesn't have a DVD add-on, this could be huge.

Although, when MP3s arrived at Amazon most people stuck with iTunes. Netflix might have enough brand recognition to prevent more than a handful from switching unless Amazon launches a serious campaign.

Edit: The other nifty part is Amazon offers video on demand for free with some DVD/Blu-ray purchases. Sending those along speedily plus instant watch also helps people choose Amazon over the local Target, Best Buy etc.