What is a good duration for a Terminus advertising tactic?

While a typical Terminus advertising tactic may run anywhere from 30-90 days, most customers align their advertising strategy, (re: duration and budget), to their sales cycle and the specific buying stage the accounts they are targeting are in. 

As a rule of thumb, your Terminus advertising creative should be updated (new creative sets swapped in) within an individual tactic every 4-6 weeks, especially if you intend to run ads to the same list of accounts for longer than that.