An online rebate system is disclosed. The online rebate system allows purchasers of products to gain nearly immediate determinations of whether they are eligible for any rebates. In one embodiment, a purchaser can provide a transaction identifier for a prior purchase transaction to the online rebate system, and then the online rebate system can examine the transaction, including the products purchased, to determine in near real-time whether the purchaser is entitled to a rebate. If the purchaser is entitled to a rebate, payment for such rebate can be automatically initiated. In the event the purchaser is not entitled to a rebate, the purchaser can be so notified.