Escrow service for the internet has been around as long as internet auctions, or shortly after internet auctions started. Much as with real estate escrow services, the internet escrow service holds funds until both parties are satisfied that the transaction contract is fulfilled and the monies can be released. If at any point there is a dispute, the process then goes into dispute resolution. The outcome of the dispute resolution process will decide what happens with the money held in escrow.
Be aware that bogus escrow methods have been employed online. The perpetrator of the scam persuades the victim to use a third-party escrow service in the transaction. The victim is unaware that the escrow site has been created by the perpetrator for the purposes of scamming the victim. The site closely resembles a legitimate escrow service. The victim sends the payment to the phony escrow company and receives nothing in return. Or the victim sends the merchandise to the perpetrator and waits for the payment through the escrow site which is never received.
Genuine online escrow sites will be listed on a government register and it is advised that you should never use an online service without verifying that is a genuine escrow service by checking the government register.