Branded campaigns are paid campaigns targeting the name of your own company or product. In reports they look excellent – a low cost per click, a high conversion rate – except that most of these customers would have come to you anyway without the ad, via the organic result. The real benefit is therefore lower than the reported return shows. This does not mean they should be switched off. They make sense when a competitor is advertising on your name, when your organic position has weak coverage, or when you want to control the wording and landing page. Verify the benefit with a test: switch off the campaign for part of the territory or period, and compare the total number of orders, not the number of conversions from the campaign. The result tends to be a surprise.
See also: Incrementality, Geo experiment, Trademark in advertising.