Even though we use machines, we use them in a way that they act like humans, and humans sometimes take naps.
So, if an ad is published and removed within 10 minutes, it's a big chance we missed it. Some domains have teams that actively block our "collectors"; therefore, we cannot always keep up with all new Ads published, and we make a sub-selection there.
Please review our blog post on Collecting data to get more insights. https://legentic.com/resources/what-is-crawling