Inbound marketing is a set of marketing strategies and techniques focused on pulling relevant prospects and customers towards a business and its products. Inbound marketing is becoming widely accepted because it complements the way buyers make purchasing decisions today—they are using the Internet to learn about the products and services that best meet their needs.
B2B inbound marketers offer their audiences useful information and tools to attract people to their site, while also interacting and developing relationships with these potential customers. Inbound marketing tools include blogging, content publishing, search engine optimization and social media.
Inbound marketing contrasts with traditional outbound marketing, where businesses push their messages at consumers. With techniques that include direct mail, telemarketing and trade shows, outbound marketing has become less effective over time as buyers have behaviorally and technologically (e.g., DVR, spam filters, 'do-not-call' lists) tuned these interruptive campaigns out.
Source: Hubspot, The 2012 State of Inbound Marketing