Many Adwords and Bing Campaigns fail to have the brand names as negatives. When this happens your conversion rates can be misleading. Consider this example:
I have an adgroup for the keyword: Digital Marketing.

When I compare all ad groups, this one may have a higher conversion rate than expected due to the brand searches that sneaked in.

This can result in misallocating resources. You may decide to increase bids on this group when it doesn’t deserve it. Therefore, best practice is to ad negatives for your brand name on all ad groups.

If you want to advertise on your brand name do that in a separate campaign or adgroup. Don’t forget to add trademark symbols ™ & ® etc.