Keep in mind that much of Facebook's purpose in buying WhatsApp was protection against it becoming the dominant player in social media. Facebook is always needi

Keep in mind that much of Facebook's purpose in buying WhatsApp was protection against it becoming the dominant player in social media. Facebook is always needing to protect itself against being overtaken by the Next Big Thing, so their strategy is to buy potential competitors before that happens. WhatsApp had a steep upward velocity, so the price Facebook paid for it was based less on its current worth and more on its trajectory.