> You can mitigate it with infrastructure changes like aggressive caching Rate data has a very limited validity period. Customers get super super pissed (and

> You can mitigate it with infrastructure changes like aggressive caching Rate data has a very limited validity period. Customers get super super pissed (and assume you're scamming them) if when they click through they find out that the hotel/flight/whatever that on the previous page you had said was $200, is now either $250 or sold out. Customers, and the local authorities also tend to get lawyers involved if it happens (in their eyes) too frequently without a good explanation. It's expensive to get that rate data, because unless you have your own inventory, you have to go out to third party APIs to request that rate for the search parameter tuple which has a specific checkin/checkout dates. When you're searching larger cities - where you might have thousands of hotels - that can be an insanely large number of API calls to return rates. Most places (including my former employer) don't have a problem issue with scrapers, so long as they didn't abuse the platform to the point that it was causing a ton of extra load. When you have someone who spins up huge numbers of connections at once, that's when we have to do something about it. > you can charge for access for everyone That's implicit in the purchase process. It's like if there's a little cafe that provides free water and tables to sit at on their balcony. That works out for them because it attracts customers. Not everyone might buy something, but most do. Then someone who runs a dog walking business decides to make that a stop on their walk with 20 dogs. Their dogs eat all the treats, run around the balcony, while the walker sits at the table and drinks the water. Meanwhile, customers are annoyed that there's now 20 barking dogs running around and so they leave. The business is well within their rights to tell the dog walker to leave and not return without also blocking others who aren't abusing the system.