A:Answer Easy Replenish is a service offered through Best Buy. It sends you whatever ink cartridges your printer uses when your printer needs it at a 10% discount and free shipping. HP Instant Ink is offered through HP. With this program you do not buy ink but pay based on pages printed, not ink used. There are different monthly plans, $2.99 for 50 pages, $4.99 for 100 pages, $9.99 for 300 pages and also some business plans for even more pages. When the printer needs ink it uses the WiFi which notifys HP who then sends you a super XL set of ink. You do not pay for the ink or shipping, just your monthly plan.