Online Marketing is very interesting. There is an entire cottage industry of persons working in marketing and working entirely online. The infrastructure around this is getting more robust all the time. There are content curation and provisioning companies, and many major long standing vendors offer affiliate channels to encourage web creators to post affiliate linked ads on their sites. Although the conventional "purchase ad, and place online" model appears to reign supreme, there is this substantial, though smaller independent, third party marketplace where content creation, marketing and product curation and hosting is operating on a different basis.