In one embodiment, a method for making an payment from a buyer to an online seller includes providing the buyer with a mobile payment application that is operable when run on one or more processors of a mobile device of the buyer to effect payments to the seller using a payment service provider. The seller is provided with computer code that is operable when run on one or more processors of a web server of the seller to detect whether a mobile device of a buyer in communication with the server has the payment application installed thereon, and if the server detects that the buyer's device has the application installed thereon, the seller's server automatically redirects the buyer to a web server of the payment service provider to effect a payment from the buyer to the seller using the mobile payment application.