It now develops and runs online sports stores for its clients and conducts affiliate marketing to drive traffic to their websites.

The watchdog said it was writing to companies identified as being involved in 'affiliate marketing'.

Merchants that were either indifferent to or supportive of adware were exposed by affiliates, thus damaging those merchants' reputations and tarnishing their affiliate marketing efforts.

In an effort to generate some income, 1999 also introduced advertisements, subscriptions, and an affiliate marketing program to the site.

The book includes chapters on different internet industries, such as e-commerce, search, advertising, affiliate marketing, domain names, and social media.