First of all, what is incognito?
Incognito is an online private feature that doesn't store your browsing history.
What are the advantages of using incognito?
It saves you the pain of cleaning browser history.
It doesn't save your cookies and you don't have to clear your cache. Stored browser history and cache can happen to create some minor 'look-a-like bugs' when showing your banner. Therefore, without any of these stored this won't be a problem.