Big companies working with affiliate networks often forbid publishers to lead traffic based on their brand search queries because they don't want to pay for their own organic traffic.

Meanwhile publishers often try to hide from an advertiser the fact that they lead traffic based on a brand search query. Tracking process is really hard. The most brands solve this problem by hand - through tracking brand search queries on their own, but this process takes a huge amount of resources. The problem becomes even more complicated if the search engine shows a fake website as a brand search query which directs users to an advertiser's landing right after a second transfer.