system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do hotel booking websites like Trivago or Expedia work? Why are their prices cheaper than when you book through the hotel?

Is this a scam? Or are these websites legit? If so how are they so cheap? Does anyone have experience with booking through websites like this?
gpt
The websites are legit and they get paid commission by the hotels, because they are handling millions of bookings their administration and advertising costs per booking are tiny in comparison to the hotels so they can have cheaper prices.