Hello.
On a Marketplace-type website, when a customer buys an item belonging to one of the sellers on the marketplace, a payment gateway, such as Paypal, manages the transaction and sends a small percentage of the transaction to the Marketplace itself. This small percentage is the marketplace's fee to the seller for enabling the seller to be able to list the item they want to sell on the marketplace.

Can an Ethereum smart contract be written to perform this transaction function, using cryptocurrency, on an ecommerce marketplace website?
Is there such a thing as a smart contract template that provides this function?