A year later Facebook founder and CEO Mark Zuckerberg did what he should have done instead of releasing Poke, offering $3 billion to buy Snapchat outright, but it was already too late: Snapchat founder and CEO Evan Spiegel, perhaps emboldened by the then-widespread realization that Instagram had sold too early, turned the offer down, leaving Facebook to try its hand at Slingshot, another Snapchat clone; that failed too.
Source: The Audacity of Copying Well – Stratechery by Ben Thompson