In this case the person looking to buy a domain should first check the terms of their Living Will, for I fear anyone paying to make an offer is certifiably brain dead, which could result in friends pulling their plugs once they learn of this behavior.
It's a good idea, in some respects. It proves that the person making the offer is genuine (in that they were willing to spend $19 for a "chance" at presenting the offer to you) and NS has their credit card/banking details so the prospect of fraud is lowered.
From a buyer's perspective, this may be a more professional way of disguising their identity than hiding behind Hotmail or other free email accounts and playing dumb about their company name. For a busy executive, the time saving alone of not having to keep checking a free account that's used for no other purpose than disguising their identity for a domain purchase approach may be instantly "worth" $19.
From a seller's perspective, there's the slight anti-fraud reassurance I mentioned above, plus there's at least the hope that you're dealing with somebody so inexperienced in domain matters that they're incapable of doing a Whois lookup - in other words, easy pickings... Also, unlike Sedo or other domain sales venues, the BUYER automatically picks up the transaction costs in this system, meaning that the seller can bank 100% of the offered amount.