Banner ads on a site or a network (like the Google Display Network) are a great way to get reach, a visual message, and clicks for a campaign. But lurking behind all those clicks and impressions are brand awareness.
Through re-targeting and following a person or device you can show them a number or a sequence of banner ads. Every time a person is shown an ad they may notice it and its message or offer (the higher the frequency the better). There is no click, but there is awareness of your brand and your message; there are other influencing factors such as device, time of day and the person’s mindset when they see your ad. This is qualitatively quantifiable if you track view throughs and brand awareness especially for converged campaigns where online banner ads are used as part of a larger integrated campaign.
This brand awareness benefit is also a benefit of running social media ads and other online ads that you may see, not just traditional old-school banner ads.