What with all the talk about bot abuse in this thread, an API may not be a good idea
An advantage of an API is that keys can be revoked for bad actors, so it at least gives some measure of control where there was none before.
I tend to agree that the lottery is the way to go for popular sites instead of first-to-book; it's fair and stops older folks from never getting a booking because they don't know how to build a faster bot.
There are a few other very effective hacks that I am loathe to publish here, but there _are_ ways to get sites for the determined.