It increases the clickable area that will result in a visit to your site, it blocks others from taking up any of that critical real estate (via ads or organic r

It increases the clickable area that will result in a visit to your site, it blocks others from taking up any of that critical real estate (via ads or organic rank), and like others have said, it's probably relatively cheap for the brand owner to bid on their own brand. I think increasing the clickable area is pretty important, especially with mobile users. And customers, since they know it's an ad, might be nice and click on the organic link instead. :-)