The low buy-in price is what will hook people, but the $15/month will get old quickly. $15/month for DVR and guide services is insane. Tivo isn't the only game in town any longer, but they are still charging people like they are.
Yes, there is a monthly fee, just like there is with most cable DVR subscriptions. At $50 the OTA Roamio is sold at a loss and the monthly fee is where they make their money. It does include the automated programming guide, which is quite good, but not worth $15 per month by its self either. It does however give you the ability to set up season passes to automatically record your favorite programs without any additional set up on your part. You also have the option to pay a one time fee of $499 and be done with it. Yes, that is a hefty price but my original TiVo is 6 years old and going strong, so the one time $499 fee becomes pretty cheap over time. I find having a TiVo with a decent OTA antenna has kept my family happy with OTA programming and some supplementation with Netflix for six years now. It has saved us over $6,000.00 in cable subscriptions over that time period. Certainly OTA TV won't satisfy everyone. Sports fans in particular will probably not find enough programming available on network TV to keep them happy. But for many it is a great way to still have some decent TV entertainment options without the ever increasing cable and satellite costs.
@ TiVoCableCutter... I hear you. I'm using an OTA DVR called TabloTV ($149 lifetime for guide services) with a 1TB WD external drive and have been nursing my family off of cable with that and subscriptions to Hulu Plus, Netflix, and Amazon Prime. I was already paying for Amazon Prime for the delivery service and Netflix even though I had cable. So Hulu was really the only add-on service for me.
I bought my own cable modem, a couple of Roku boxes and a magicjack network connected device ($2-3/month unlimited phone service depending on the payment plan you choose). I already have everything in place and we will be officially "cutting the cord" on Sep 2 and going from a $190 cable/phone/internet bill to a $30/month internet bill (30Mbps)/month. In three months, I'll have paid for the additional hardware (based on the savings) and from that point on, it's $150 in savings/month. I was paying approximately $40 just in equipment rental (1DVR, 2 HD and a cable modem) through comcast!
With that TabloTV, I'm able to broadcast Live and recorded TV to my Android Tablet, PCs, Roku boxes, iPad... pretty much anywhere in my house now.