Founder Gets Avalanche of Money to Stay at Tumblr If he sticks around til June 2017, David Karp gets $81M By Arden Dier, Newser Staff Posted Aug 9, 2013 11:17 AM CDT 4 comments Comments David Karp reacts during the opening bell at Nasdaq, Thursday, July 11, 2013 in New York. (AP Photo/Mark Lennihan) (Newser) – Tumblr founder David Karp has about 81 million reasons to spend the next four years working his current job. The $1.1 billion sale of his baby to Yahoo back in May includes a retention payment of $81 million—$41 million in stock and $40 million in cash, the AP reports, via a regulatory filing yesterday. But the 27-year-old has to stick around until June 2017 to get the full payday. The AP notes it'll likely be a second windfall for Karp, who is thought to have as much as a 25% stake in Tumblr and would have gotten a chunk of change from the sale. One more detail from Yahoo's filing picked up by AllThingsD: Tumblr had $16.6 million in cash when Yahoo bought it. With 175 employees, Peter Kafka writes that Karp would've had to raise more money relatively fast had Marissa Mayer not stepped in.