The counter at the bottom of the page updates in real time as you make selections. The rule: each audience type you select is multiplied by the number of retention periods selected. For example, 3 Instagram engagement types with 3 periods create 9 audiences. There are exceptions: Profile followers (Instagram) and Page likes or followers (Facebook) count as 1 each because they don't use a period, and Lookalikes count as the number of sources multiplied by the selected percentages. The Create Audiences button is enabled only when the counter is greater than zero. If a required item is missing (account, Instagram, videos or periods), the system shows a warning telling you what to select.