For all deals in the Travel category, price comparisons are based on the price at which the merchant makes that service available to non-Groupon customers. In order to ensure that the information we are given by merchants regarding their prices is accurate, we verify the reference prices shown on the deal page in the following manner:

• for Voucher deals, the reference price is verified using public sources such as major third-party travel sites such as booking.com, or the merchant's own website. The exact source and date of price verification is indicated in the fine print of each deal. If we are not able to verify the reference price (for example if the merchant does not have a price list available online) we will not indicate a reference price.

• for Direct Booking deals, the reference prices are verified for each date based on the rates available on booking.com at the time of verification. The verification date is indicated in the fine print of each deal. If we are not able to verify the reference price for a given date (for example if the merchant does not have a price list available online) we calculate the closest approximation using an average of the available rates, or we will not indicate a reference price.

For all deals, price comparisons are calculated based on the lowest price available on the relevant source at the time of verification. However, while the sites we use for price verification offer very competitive prices, they may not always reflect the cheapest rate available anywhere on the Internet. Prices on many sites such as booking.com also evolve dynamically, meaning that they change from time to time. This is why we indicate the exact date of price verification in each deal in order to ensure maximum fairness and transparency.