A very high spending account may need daily or even hourly changes. For accounts with smaller budgets, there may not be as much maintenance involved.
Similarly, this depends on if we’re achieving our goals or not. If we are, we may make slower optimizations (to not deter the performance of the campaign). If we aren’t hitting our goals, we make more frequent optimizations until we start achieving them.
On average, we generally make changes in an account every 3-7 days (again, depending on how much activity the campaign gets and your specific goals).
Too many changes harbors an ecosystem where it’s hard to keep track of the outcomes; making changes too infrequently means competitors may outperform your campaign.