Internet usage around the world, especially in the wealthiest countries, has steadily risen over the past decade and it shows no signs of slowing. According to a report by the Internet trend investment firm Kleiner Perkins Caulfield & Byers, 245 million people in the United States were online as of 2011, and 15 million people connected for the first time that year. As Internet usage grows, online commerce grows with it. This means that more people are using the Internet with each passing year, and enough of them are spending money online to impact the economy in significant ways. (See also E-Commerce Marketing)
A disadvantage of digital advertising is the large amount of competing goods and services that are also using the same digital marketing strategies. For example, when someone searches for a specific product from a specific company online, if a similar company uses targeted advertising online then they can appear on the customer's home page, allowing the customer to look at alternative options for a cheaper price or better quality of the same product or a quicker way of finding what they want online.
Affiliate marketing overlaps with other Internet marketing methods to some degree, because affiliates often use regular advertising methods. Those methods include organic search engine optimization (SEO), paid search engine marketing (PPC – Pay Per Click), e-mail marketing, content marketing, and (in some sense) display advertising. On the other hand, affiliates sometimes use less orthodox techniques, such as publishing reviews of products or services offered by a partner.