It works but it was installed in 1967 so I need to prepare to replace it when it fails at some point.

I would not characterize this as a scam per se.. but it appears to me to be a failed investment model..

At this point, they are doing most likely what others here didn't think was possible, and probably something they failed at. 

The internet companies that failed, failed because they didn't have a viable product or service, not because of the underlying technology of the internet.

I know of people that set up an LLC for every property but then they fail to maintain them properly. 

If they fail to pay the taxes, plus fees and interest, within that time, then the property legally becomes yours.

So now I get an email from RentRedi EVERY DAY that says "your payment method has failed".  

Harder to liquidate, amplified results if you fail, and cash flow less.Pull a list and cold call, or develop relationships with brokers.

OR you are paying for it with a failed promise. 

Once we missed the closing date, the seller wasn’t happy & demanded the EM of $10,0000 be released to him & put the house back on the market.We ended up with an extension only because we had been in a state of emergency and the lender had 8 more days to come thru & they failed us!