Web marketing, also referred to as i-marketing, internet-marketing, online-marketing, Search Engine Marketing (SEM) or e-Marketing, is the marketing of products or services over the Internet.

The Internet has brought media to a global audience. The interactive nature of Internet marketing in terms of providing instant response and eliciting responses, is a unique quality of the medium. Internet marketing is sometimes considered to have a broader scope because it not only refers to the Internet, e-mail, and wireless media, but it includes management of digital customer data and electronic customer relationship management (ECRM) systems.

Internet marketing ties together creative and technical aspects of the Internet, including: design, development, advertising, and sales.

Internet marketing also refers to the placement of media along many different stages of the customer engagement cycle through search engine marketing (SEM), search engine optimization (SEO), banner ads on specific websites, e-mail marketing, and Web 2.0 strategies. In 2008 The New York Times, working with comScore, published an initial estimate to quantify the user data collected by large Internet-based companies. Counting four types of interactions with company websites in addition to the hits from advertisements served from advertising networks, the authors found the potential for collecting data upward of 2,500 times on average per user per month.