When Twitter (NYSE:TWTR) asks for your birthday it's not just so the company can Tweet you virtual balloons and your friends can fill your feed with #HBD remarks.

Those things will of course happen if you wish to make the day you were born public information, but facilitating celebration is not the only motive behind Twitter's actions. The company wants to know your birthday -- and other milestones in your life -- in order to better sell aggregate data to advertisers.

The birthday tracking is simply part of an overall program by the social media website to make its users more relevant to the businesses buying ads. There's nothing wrong with that -- it's something other social media websites do -- but the company may be going a bit overboard in how it's selling the program to users via a blog post announcing the ability to add birthdays.

Every day, millions of people celebrate the important events in their lives on Twitter — from public events like the recent U.S. Supreme Court ruling that ignited #LoveWins to more personal ones like a friend's birthday. We're excited to make sharing these personal celebrations even easier — starting today, you'll be able to show your birthday on your Twitter profile.

It's a bit of a leap to link sharing your birthday with your Twitter followers to a historic Supreme Court ruling, but the company was not likely to be straightforward and say "share your personal info so we can package it to advertisers."

The company is using comedian Kevin Hart as its example of how sharing your birthday can be a positive thing. Source: Twitter

What is Twitter doing?
Twitter has built a large audience on its platform but it has struggled to monetize that asset. To attempt to improve that, the company has launched a number of improvements to is audience insights dashboard. The new dashboard will allow advertisers to "access key insights about the people they reach with ad campaigns and through tailored audiences," according to a blog post. "These aggregated insights, provided by Twitter data and Twitter Official Partners Datalogix and Acxiom, offer valuable information about user demographics, interests, purchasing behavior, and more. They allow marketers to pinpoint and target new audiences on Twitter while keeping user information private."

The company has also introduced "Personas," a way to target relevant groups of users in campaigns "with a single click."

Twitter has broken down a number of groups for advertisers. Source: Twitter

Of course, for Twitter to share this information it has to know it in the first place. That's why the company must find ways to sell users on sharing relevant data.

Will this work?
What's notable about these efforts is how late in the game they feel. Facebook (NASDAQ:FB) has made collecting this sort of data a basic part of its registration and profile process. Setting your birthday, marital status, and sharing other info, such as where you went to school, happens organically.

Because Twitter did not build sharing that info into the user experience on its site, it has struggled to collected the data. It's relatively easy to add your birthday and other info, but there's no real reason to do it. I use Twitter almost everyday, but won't add this info just because Kevin Hart looks like he's getting some extra birthday wishes.

This is a smart, albeit clumsy, move for Twitter and its advertisers. Certainly some users will participate even if only for narcissistic reasons, and that will give the company more data it can sell. It would have been much better for the social site to have been collecting birthdays all along, but it's better late than never.