Online payments for a middleman
问题 I'm new to online payments and would like some opinions on my task. Here is the scenario: I have a website where people buy and sell digital photos. A seller has a photo and wants to sell it. They create an ad on the site and upload the photo into the website database. Buyers looking for photos come to the site and buy them. The buyer pays the asking amount and then can download the photo. As the middleman, I'd like to charge the seller a fee or percentage of the selling price. The buyer