Innovative idea #00. Let people sell their new and old stuff

Maybe this won't take enough sellers, but I found really awesome idea through selling new stuff myself: http://new.market.yandex.ru/#new - this service offers model called CPA (Cost Per Action) and this is offered by our largest Russian retail advertiser - Yandex.Market. The whole case with Yandex.Market and reason why users choose it - it is ability to search products on their web-site. Okay. But how about payments, who the heck would want paying for something without seeing?
Client is someone who's often not satisfied with just pre-order. Let's just take example of usual (old school) sales model versus new model:
1. User pick some good on the web-site, and according to describtion he just pays that order, because user trusts the web-site, and the fact that if he won't like the good for which he has paid, then no browblem.
2. Once user picked and payed for the good, seller sees that and he likes that, because that means that user got enough money.
3. Let's imagine that we introduced new system of confirming orders through telephone call to our call-center. If user likes the good, he can say to operator the secret word he chosen. EfxEtm Password Choosing Just For Them: You can pick the pin-code if you want to let seller to confirm payment in case if the user doesn't have the phone with himself.
4. What wrong can happen? Nothing. Everything is secure. Even worse: we will have such system - in case if pin was said wrong, the payment isn't goes to be withdrewable 3 days later. Why? Because imagine if you're going with huge amount of money like $10,000 to seller, and the seller is a terrorist who's going to leave country once you brought him money, and he will left you alone dying, yoknow while he escapes country. Sounds ridiculous, but it may happen. Sh*t happens. Okay in this case you're telling the wrong (police) pin and the hostage keeper doesn't knows that-this-is the wrong pin, so, police gets notified about such pins. If police doesn't wants to get notified or think that users are stupid on this service, then police wrong, because we will put a caption in an agreement with user who is identified himself anyways to a service. YoKnow in this case user can't do anything wrong. BECAUSE PIN MUST BE CORRECT NO MISTAKE MADEN.
And when police receives the wrong pin, the police also must receive the address where the customer last time was. But lets imagine that you were put into car and was driven somewhere else in the dark places. Then our web-site is useless and can't save the person even if the person said the wrong pin, but in this case person can change his mind and say the correct pin, then no problem for person's health.