inspiration

The inspiration for WhatsApp came after both founders left their jobs at Yahoo in 2007 and took some time off. Acton moved to New York to live with his girlfriend (and at one point proclaimed on Twitter that he had applied for a job at Facebook and had been rejected). Koum did some traveling to Argentina and other countries and realized that it was difficult to stay in touch with friends.

International area codes made it difficult for people to call him. Email was simple, but it was not as streamlined as a text message. Text messages, however, were expensive, costing at least 25 cents for each one sent from Europe to the United States. And online chat services from Google and AOL required knowing people's screen names.

Two years later, Koum returned to the United States, bought an iPhone and reunited with Acton to build WhatsApp. The service would take advantage of a phone's address book to make it as streamlined as text messaging, and it would be nearly free like other internet messaging services. Privacy was vital.