David Karp says Tumblr has a 'lot to prove' 18 months after Yahoo acquisition

Even though Tumblr has finally started to generate revenue for Yahoo, founder David Karp said today the companies still have a lot of work ahead to convince skeptics the deal was a good one.

“We have a lot to add and a whole lot to prove,” Karp said while speaking on the main stage at the Web Summit in Dublin.

During Yahoo’s most recent earnings call, chief executive Marissa Mayer surprised analysts by revealing that Tumblr is expected to generate $100 million in revenue in 2015, making the subsidiary profitable on an operational basis. Mayer said Tumblr’s sponsored advertising was on the rise thanks to an audience that has grown 40% to 420 million since being acquired.

Yahoo made big waves in 2013 when it bought Tumblr as part of Mayer’s big plan to turn the lumbering Internet giant around. Karp said his relationship with Mayer remains strong, and he gave her credit for accelerating Tumblr’s growth.

Still, he said, Tumblr was continuing to work on new products and features to attract new users as well as to help companies and brands connect with its relatively young user base.

“Our mission is to continue to expand the canvas for this army of creators out there in the world,” Karp said. “I hope we get a lot more attention and appreciation for what we’re doing.”