Maybe it is just my IRL business experience, but something tells me that most people holding an asset worth $100K or more wouldn't seriously entertain, let alone hand over the family jewels, to just anyone offering a purchase out of the blue.
How many people would give a person, who just showed up at their doorstep saying they want to buy your house for $xxx,xxx , a grand tour? Sensible people would treat that person with great suspicion (though it is true that thieves scam their way into people's houses all the time - often the elderly).
Absolutely forget it for a $1M+ site. You'd need representation, from, say, a broker. You'd probably need to put down some earnest money in escrow to prove you are serious, or at least have some bank approved documents to show you have the money.
Sorry, but I only see this working on the least astute "competitors" out there, which probably means that they are somewhat easier to beat through legit strategy and tactics, anyway.
IMHO.
