The FBI is now turning to social media through paid ads to help finally learn what happened to Rachel Cooke.

It's an unusual approach that comes as part of a renewed effort to help solve the missing persons case from 2002.

Over the past 15 years, investigators have relied on all kinds of approaches -- from tip lines to increased cash rewards. Now, they say it's time to draw interest where many people get their information and spend a lot of time these days -- from sites like Facebook.

A paid ad that recently started popping up on Facebook has two pictures of Rachel Cooke -- and gives a bit of background about her case. So far, it has been shared more than 530 times among Facebook users alone.

It also gives a number for tips: 1-800-225-5324.

This social media campaign comes a couple of months after Williamson County Sheriff Robert Chody and other authorities announced a $100,000 reward for information in the case.

It's a case that has frustrated law enforcement for years. Cooke vanished after going for a morning run while at her family's home outside Georgetown more than a decade ago.

Investigators have pursued numerous tips through the years, but none have led to conclusive information about Cooke's whereabouts or who may have harmed her.

When Sheriff Chody took office in January, he created a new cold case team to help solve this case and about a dozen others. KVUE and Austin American-Statesman reporter Tony Plohetski checked with that team on Tuesday, and they said they are working on finding out what happened to Rachel Cooke every day.

Meanwhile, no information was available Tuesday about how much the FBI is paying for this social media ad campaign and, more importantly, whether it has generated any new leads in this case.