Business-to-business (B2B) marketers hesitate to embrace social media as a marketing tool, unlike their business-to-consumer (B2C) counterparts, and they struggle to implement successful social media strategies due to their limited understanding of the phenomenon. Drawing on communication and word-of-mouth theories, the authors investigate how marketers use Twitter differently across contexts and predict key factors likely to influence the message strategies used in each. A longitudinal content analysis and logistic regression support the assessment of a sample of more than 7000 tweets by Fortune 500 companies. Marketers in B2B and B2C settings exhibit significant differences in their branding and selling strategies; their use of message appeals; and the use of cues, links, and hashtags to support information searches. Whereas B2B marketers tend to use more emotional than functional appeals in their tweets, neither B2C nor B2B marketers have adopted “hard sell” message strategies.