Thanks to the way the commission payments are structured, the more bookings that users make through your links, the higher the commission you'll receive. The rates start at 25 percent and go up to 40 percent once you've surpassed 501 bookings. To clarify, that means 25 percent to 40 percent of Booking.com's commission, so don't expect to get that percentage of the overall cost of the hotel stay.
Always disclose your affiliate relationship. Most visitors will probably understand that graphic ads will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.