When building a keyword list for a Display Network campaign, you should do which of the following:
- Use Display Campaign Optimizer to identify new keywords
- Only include exact match keywords
- Only use Keyword Planner to identify new keywords
- Include keywords that are related to the websites your customers visit
Choosing keywords for a Display Network campaign is about connecting your ads with people most likely to be interested in your business. Based on what you know about your customers, pick keywords that would you imagine would appear on websites your customers would visit.
Read more here: https://support.google.com/adwords/answer/2453986?hl=en
when building a keyword list for a display