Bob has come across these 24 hour open house signs in his Arizona sub-division.
The OpenDoor brokerage offers a little twist on selling a buying homes. They generate a fair market value purchase offer online using their data. I suppose the number is either good enough for you or not. Good... they "take care of everything" and you move when you are ready. The homes they list are vacant and available for viewing 24hrs. It looks like they fix-up the homes they buy a little, stage and re-sell.
Access entry instructions with your smart phone.
I suppose this all works in certain circumstances. I'd be comfortable buying this way... but I buy a lot of houses. I'd rather put my home on the open market at the right time than take an offer from an algorithm. It all has a foreclosure/ short sale feel to it.