Internet marketing covers all aspects related to the promotion and sale of a product or service through the Internet. This chapter demonstrates how adequate planning is fundamental in a Small and Medium-sized Enterprise (SME) to increase sales. The objective is to analyze the aspects which must be taken into consideration when developing a good e-marketing strategy and to study some of the different alternatives that the Internet and e-marketing make available to us: e-mail marketing, viral e-marketing, geomarketing, and positioning within search engines. Also the concept of Customer Relationship Management (CRM) will be analyzed. The leap into the global market is not easy and the reduction in budgets has inspired marketing professionals to adopt strategies which can be measured and the results controlled, pointing out that the online tactics and tools used by the vast majority of marketing professionals in their strategic plan are banners, search engines, and e-mail.