News out of Menlo Park: The formidable Facebook will release its diversity report and the word is that things have improved, but not enough to satisfy the company's leadership. So, an insider explained to Bloomberg, the company is instituting the Rooney Rule. The Rooney Rule, named for Pittsburgh Steelers owner Dan Rooney, requires NFL teams to interview at least one minority candidate whenever a head coaching position becomes available. Facebook is doing something similar, requiring one minority candidate to be considered for every open position. The rule has been in effect for some departments for months, and will soon be rolled out to all of Facebook, the insider said. (A Facebook representative confirmed the information to Bloomberg but did not comment further.)

In the United States, Facebook's work force is less than 3 percent black, and only 4 percent Hispanic. About 33 percent is Asian and 57 percent is white, according to its earlier report. Given those numbers, a little more diversity is certainly a good goal. And Facebook, with its 10,000 employees worldwide is an industry leader and may help bring diversity questions front of mind for corporate leaders throughout the tech world.

This is all good news-but I have some questions that, so far, Facebook is not answering.

1. What about gender diversity?

Facebook's COO Sheryl Sandberg is arguably the most famous female corporate executive in the world. And yet, only 31 percent of Facebook's worldwide employees, and only 15 percent of its technology employees are female. There's a reason, according to Facebook CEO Mark Zuckerberg: Not enough women have the engineering degrees that Facebook and most other employers are eager to hire.

Can you blame us? We've seen "The Big Bang Theory." We've firmly absorbed the idea that the world of tech is overwhelmingly male, depressingly nerdy, and that the few women who work in it are decidedly odd. Inspiring women to pursue tech careers is therefore a chicken-and-egg problem that will only be solved with scholarships, publicity campaigns, and some big systemic changes throughout the industry.

All this will take time. In the meanwhile, it's depressing to note that the Rooney Rule-appropriately selected from a sport where the only women are cheerleaders-does not suggest anything about interviewing female candidates. Apparently that's not part of Facebook's diversity plan.

2. The Rooney Rule only applies to interviews.

The question of actually hiring a minority job candidate is entirely voluntary. So managers who aren't inclined toward diversity can simply "consider" a random black or Hispanic, then hire whomever they please.

Indeed, this seems to be what happened in the NFL in 2012, when the Rooney Rule spectacularly failed to produce a single non-white hire. But because the Rooney Rule is a well known initiative aimed at a very small number of extremely high-profile jobs, that failure was very visible and resulted in some publicly expressed concerns from the NFL. It's an open question whether the same tactic applied to thousands of hires being made in relative obscurity will have any effect at all.

3. Is this really just a form of marketing?

Here are some Silicon Valley companies that have made public statements that they seek to increase diversity and/or be more welcoming to women: Twitter, Apple, Google, Facebook. Here's what those companies have in common: They are aimed at consumers and a lot of those consumers are non-white, non-male, or both. Being able to better serve all customers and not just white male ones is a powerful argument for diversity at consumer tech companies. For instance, many observers (including me) have noted that a more diverse Twitter might have dealt better with that service's rampant misogyny and racism.

Unfortunately, Silicon Valley's default culture is white male only, as the infamous Startup Castle ad beautifully displayed. Most tech companies have few incentives to change. In the greater world of tech out there, most companies are not aiming their products at consumers, but at other businesses. That means the customers they need to persuade are executives, especially tech executives, often at very large companies.

And we all know how diverse a group that is.