Nowadays, it is not uncommon for someone to come across a 'model' online, and there are a number of different platforms where they can be found. And while some of these models typically keep most of their closes on, there are others who typically keep most of their clothes off.
Along with this, there will be some models that do this for a living; while there will be others that don't. If a model does, they might make most of their money sharing pictures of themselves holding, or wearing, different products.
Another Way
Promoting different products is then going to be a way for them to make a fair amount of money. Some of the people who follow them may also send them money directly, even though they may get very little in return.