What will Tivo tell you about the TSN of a used unit?

Try to add the TSN to your account before purchasing. If the Tivo is on another account, you will get a message telling you so and you won't be able to add it.

If you call TiVo, the only thing they will tell you is the current status of that particular TSN (subscribed, unactivated, etc.).
If the Tivo is reported to have lifetime service, I think TiVo will confirm or deny that status.

I don't know what info they'll give to those without TiVo accounts, but I can call or do the online chat thing, tell them I'm thinking about buying a used unit, and give them the TSN, and they'll tell me if it's lifetimed or not, and when it was first put into service, but nothing, nada, zip, zero, about names or addresses of previous account holders, even on the 2 used lifetimed S1s on my account.

What I do is type up my name, address, phone number, explanation that I'm looking to buy used unit(s) and TSN(s) of said unit(s) in Notepad, and then do the online "chat" with customer service and paste it all in at once to save everyone time.

Before you buy from eBay, use Google to search Craigslist nationwide. I've seen 2 S2 DTs being given away for free in the past week, and "never been used, never taken out of the box, bought at Blockbuster/Circuit City/wherever on closeout, received as gift, etc., but never subscribed" units are coming out of the woodworks.

Yes, Blockbuster still had some S2's for sale (multiply that by a good number of stores. The one I was at had 3 for sale), but even higher than what TiVo was selling them for near the end.