• by Gavin O'Malley , Staff Writer @mp_gavin, February 20, 2017

Ahead of its big IPO, Snap, Inc. is losing one of its top ad executives. Yes, about a year after leaving Facebook for the Snapchat parent, Sriram Krishnan is heading for the door.       

“After a great year at Snap, I’ve decided to leave and move back to SF to be closer to [my wife Aarthi Ramamurthy], family and friends,” Krishnan tweeted on Sunday.

Of course, the timing stinks for Snap. The company is in full road-show mode, as it tries to get investors pumped for its highly-anticipated IPO.

While Snap is trying to diversify its business, advertising is still everything to the company.

Indeed, as it recently revealed in an S-1 filing, advertising accounted for 96% of its revenue in 2016.

Snap assured investors in the filing: “Our advertising business is still young, but growing rapidly.”

The company saw revenue of $404.5 million last year -- up more than 600% from the $58.7 million it generated in 2015.

Along with growing membership, Snap is also increasingly making more ad revenue from each user.

Worldwide, average revenue per user (ARPU) in the last three months of 2016 was $1.05 -- up from $0.31 during the same period a year earlier. In North America, Snap’s ARPU in the last three months of 2016 was $2.15 -- up from $0.65 year-over-year.

Snap, of course, still is not making a profit. Last year, the company incurred a net loss of $514.6 million -- up from a net loss of $372.9 million in 2015.

As Pivotal Research analyst Brian Wieser suggested in a recent investor note, Snap business remains nothing if not “early-stage.”