It's big news when a company hires a chief financial officer. But when he leaves 2 1/2 weeks later -- well, apparently, no one would be interested in that news.

That's the apparent attitude of advertising technology firm

Mediaplex

(MPLX) - Get Report

, which earlier this month proudly announced that it had hired Michael Stanek, a senior analyst at

Lehman Brothers

(LEH)

, but has been sluggish about letting people know that Stanek has since returned to his old employer.

Mediaplex, which markets a system that lets companies modify ad campaigns in real time to account for changing product inventory and other factors, obviously thought Stanek was an important hire. In a release dated March 9, the company quoted its CEO, Gregory Raifman, as saying, "Mike Stanek's appointment reflects our commitment to building a world-class management team that can help with our efforts to become the global leader in advertising technologies. Mike's unique combination of strategic market knowledge and strong understanding of our financial position make him the right choice for our CFO."

But on Stanek's way out, the company didn't have much to say. Instead the company left it to Lehman Brothers to put out a press release Monday afternoon that said Stanek would be rejoining the investment bank. The Lehman Brothers release, which apparently was not transmitted over either of the major press-release distribution services in the U.S. --

Business Wire

or

PR Newswire

TheStreet Recommends

-- was picked up by

Dow Jones News Service

Monday afternoon.

It's in the realm of possibility that Stanek's departure could pose a problem for the company. In the "Risk Factors" section of regulatory filings for the company's secondary stock offering, the company notes, "The loss of our key personnel, including our chief executive officer, president and chief operating officer, or any inability to attract and retain additional personnel, could affect our ability to grow our business." It also points out "because many of our executives, including our chief financial officer, have only recently joined us, our management team has only worked together for a short time and may not work effectively together."

But one attorney suggests it's doubtful that the news is material. "Speaking in the abstract, is a departure of a CFO likely to be material? Probably not," says Steven Hansen, a partner at

Bingham Dana

specializing in securities litigation and regulatory matters. He adds that the fact that a company issues a press release upon the arrival of a new employee doesn't necessarily mean that the departure of that employee is a material development.

A spokesman for Mediaplex, when asked about the notification of Stanek's departure, referred the reporter to the Lehman Brothers release and the

Dow Jones

item. The company, which is in the midst of the secondary stock offering, isn't commenting on Stanek's departure.

But in the quiet period for its secondary offering, Mediaplex hasn't been completely silent. On Monday afternoon, the company did find the time to issue a press relase saying that it was expanding globally by opening an office in London and an ad server farm in Hamburg. The company added that it has acquired 20 new customers since Jan. 1. But it did not say anything about the CFO's departure.

Of course, the market may have already decided which news from the company is more important. Mediaplex's stock has added 13 points since Monday morning, closing at 54 on Tuesday.

Oh, well, just like they said in Bambi: If you can't say something nice, don't say anything at all.