A "casual browser" refers to someone who looks at things on the internet without a specific purpose or goal. They may just be casually and leisurely exploring different websites or content. Full definition
It's a safe bet these sales weren't from casual browsers who happened to spot her books. (annerallen.com)
The downside is that the later ones will be too high for casual browsers to generally pick up, and thus lose value as entry points into the series. (madgeniusclub.com)
Making your image look like a tangible product goes a long way in convincing casual browsers to become customers. (adazing.com)