Yahoo's recently completed acquisition of Internet blogging service Tumblr includes an $81 million payment to Tumblr founder David Karp as long as he remains on the job for the next four years.
The retention payment disclosed in a regulatory filing Thursday is part of the windfall that Karp and Tumblr investors realized by agreeing to sell the service for $1.1 billion in May.
Karp turned 27 last month. He started Tumblr in 2007, a few years after he dropped out of high school in New York to concentrate on computer programming.
(Read more: Yahoo and Dan Loeb not parting on good terms)
Yahoo CEO Marissa Mayer has pledged not to make any dramatic changes at Tumblr in hopes that the acquisition won't alienate the blogging service's existing users, which includes a substantial number of teenagers and young adults.
As part of her promise "to not screw it up," Mayer is allowing Karp to run Tumblr independently in New York. Yahoo is based in Sunnyvale, Calif.