Watch the video to learn how to create a Gmail Ads Campaign using Adwords. The steps are simple to enable this display network campaign, and you should use separate ad groups for your Gmail ads so that they are distinct from the existing display or remarketing campaigns. Using a different targeting method- for example, choosing to display ads on mail.google.com ONLY- will allow you to avoid competing with your own display ads elsewhere on the internet.
Gmail Ads display a small Logo, an image, and should include a call to action or special offer, whichever you decide. As mentioned above, only the Gmail ads targeting method & placement should be used. As well, Gmail ads can only be shown to an individual user up to four times.