Pick a few competitors (suggesting 1-6) and create a display or video campaign. Setup one ad set for each competitor. Then, build these 4 audiences within each ad set:
- Custom affinity targeting the competitor's website
- Custom affinity targeting the competitor's brand name
- Custom intent targeting the competitor's website
- Custom intent targeting the competitor's brand name
This is a highly segmented way to have an outbound campaign going to specific competitor's users/customers/leads. Affinity means it will target people who are frequently visiting that brand's site or associating themselves with that brand regularly. Intent means it will target the people who are actively researching or planning a purchase of that business.
The caveat with this campaign is, if your competitor is a SAAS product, frequent visitors of the site might be going there to login. So this means the ads will appear for the competitor's existing users. Because of this, it's recommended to test this campaign to make sure you aren't spending a ton of budget targeting primarily existing users -- and, if you are, make sure the ads feature a competitive advantage in an effort to get those users to make the switch.