Adam Marchick has stepped down as CEO of Kahuna Inc., the mobile marketing automation company he co-founded four years ago, Fortune has learned. He will transition into an interim chairman role, and at least temporarily lead product.

Board member Charles Hudson, managing partner of Precursor Ventures, will serve as interim CEO as the search proceeds for a full-time replacement.

“All I really care about is Kahuna being the next major marketing player,” Marchick told Fortune during a phone interview. “We as a board had an open and honest conversation about who is the best person to take the company to $100 million [in revenue]―that’s our next milestone―and we decided that perhaps there is someone better than me.”

The move comes seven months after Kahuna raised $45 million in Series B funding from Tenaya Capital, Sequoia Capital, and SoftTechVC (where Charles Hudson is a venture partner).

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Marchick says that the company’s original target customers were mobile apps like HotelTonight and Tumblr, which used Kahuna’s technology to personalize messaging. The Silicon Valley startup eventually determined, however, that the total addressable market wasn’t large enough.

“It was good, not great,” he says. “Great would be $20 billion.”

So the company chose to expand its focus, hoping to also disrupt the broader Salesforce marketing cloud by becoming what Marchick calls “ExactTarget for the mobile era.”

That meant quietly laying off around a dozen salespeople last November, plus parting ways with VP of sales Matt Cameron. There are no current plans to raise additional financing, as Kahuna still has most of the $45 million it raised last summer.

“We’ve been focused since the early days on omnichannel marketing, so it’s the same basic business model,” Charles Hudson explains. “But we think there is a big opportunity, for example, to bridge email and push marketing in the mobile world.”