The most popular photos that sell in stock photography are photos of people. Many photos that sell are lifestyle images that depict some aspect of an ideal world – it may be beautiful people enjoying a piece of paradise or someone celebrating the little, or not so little, luxuries of life.

Business-related photos with people in them are also among the top selling subjects at many stock agencies. These are photos that sell well.
That’s why you see so many photos of people in business settings, businesspeople holding money, or briefcases, or communicating with each other.

Photos of computers, keyboards, and mobile devices are also very popular, and once again reflect the business category mentioned earlier.

Further down the “popularity list” are  travel, nature, and landscape photos. But you may be better selling those landscapes as framed prints rather than as stock photography.

You can study and research what is selling at top stock photography web sites. They typically make it very easy to browse their most popular photos – those photos that sell best.