This placement is a popular choice in the industry and has a number of benefits, as well as some potential downsides.
On the plus side, banderole advertising places the ads at the bottom of the screen where they are going to be out of the way of the site’s content. This is a useful feature as it means that visitors won’t be put off by poor ad placement, or ad placement that is going to obscure or hide important elements.
This also means that the banner can span the entire width of the screen, which is ideal for using wider images that will contain more information.
Finally, because banderole ads at the bottom of the site, this means they are at the terminal point. This is the point at which the visitor has likely finished reading and is more inclined to follow a link to another site.
On the downside, visibility can be an issue for banderole. That’s because the ads will be displayed at the bottom of the screen and may not be seen depending on the resolution of the device. This can be good news for publishers if the payment is CPM (cost per impression) but it is bad news for advertisers who won’t get the visibility that they are paying for.