Campaigns associations are a common method of communicating to sales that a lead/contact has interacted with a marketing program.
Once challenge I've seen is that the Best Practices around naming conventions for Marketo programs leads to campaign names that are hard for sales to understand.
Working within my confines -- marketing not willing to change their campaign names & sales still needing to understand what they're looking at, below is a 'creative' solution I came up with which requires minor maintenance from marketing but has proven helpful to sales teams.