News broke earlier today that Facebook was buying popular messaging app WhatsApp for $16 billion, and while the social media giant ingesting yet another company is certainly news unto itself, the deal marks what could be one of the most successful venture capital investment deals of all time. Sequoia Capital reportedly invested a mere $8 million in WhatsApp back in 2011 — and while startups commonly raise subsequent rounds of funding amongst several investors, WhatsApp never announced any additional funding.