Because users have different operating systems, web browsers and computer hardware (including mobile devices and different screen sizes), online ads may appear to users differently from how the advertiser intended, or the ads may not display properly at all. A 2012 comScore study revealed that, on average, 31% of ads were not "in-view" when rendered, meaning they never had an opportunity to be seen. Rich media ads create even greater compatibility problems, as some developers may use competing (and exclusive) software to render the ads (see e.g. Comparison of HTML 5 and Flash).
In the 2000s, with more and more Internet users and the birth of iPhone, customers started searching products and making decisions about their needs online first, instead of consulting a salesperson, which created a new problem for the marketing department of a company. In addition, a survey in 2000 in the United Kingdom found that most retailers had not registered their own domain address.These problems made marketers find the digital ways for market development.
Push marketing is a proactive technique that enables e-marketers to "push" their product/service information to Web visitors or shoppers without their requesting it. Banner advertising, pop-up advertising, e-mail promotion, and spamming belong to push marketing. For instance, e-marketers can rent designated space from Internet service providers such as America Online or MSN for their banner or pop-up ads. Using animated graphics, appealing messages, and links, e-marketers try to lure visitors to their sites to buy their products or services. Many Internet users, however, find such ads annoying and employ software that blocks pop-ups and banner ads. <