ORLANDO, Fla. -

No matter your age, if you're single, you've probably thought about signing up for online dating.

"I couldn't get his ad, his profile out of my mind, so I finally decided i was just going to do it," said Ronda Grant, who met her husband, Ed, through online dating 11 years ago.

"We started talking, and I knew there was something different there so we met," said Ed Grant.

That led to date after date, and eventually marriage. People like Ronda and Ed fuel this billion-dollar annual business.

A new report from Men's Health Magazine shows Jacksonville ranked No. 21 in the country for online dating.  And just up the road, Orlando ranked No. 4.

But before you sign up and start searching, be cautious.

"You have thugs and predators that are patrolling the Internet every day, trying to find a victim of opportunity," warned James Copenhaver, a private investigator.

He says crooks and con artists prey on people who are lonely, going after them for money, a quick hook-up, or worse -- sexual assault.


"He starts reeling her in to the point where he'll then bump it up to a phone call, and after a few phone calls, then that predator will want to meet this female," said Copenhaver.

But, if you pay attention, you can spot the predator. First, be on the lookout for lies.

"Literally come up with some questions to ask this person, and let it go for a couple days, or even a couple weeks, and go back and ask a couple of those questions over, and see if that person gives the same answer," said Copenhaver.

When you do meet, pick a public spot, like a restaurant. And watch out for the person who tries to take you back to their place too soon.

"I think it certainly provides a temptation," said Rick Brown, a relationship therapist.

He thinks online dating has given married men and women an easy way to have an affair

"They're just feeling dissatisfied, unhappy, they're not ready to leave the relationship, but they are yearning for some kind of connection," said Brown.

If you're not careful, you could unknowingly be going out with the cheater. That's where sites like Google and Facebook may come in handy.

"Use that internet to do your homework, where you actually do an additional search on this person, see who their friends are," said Brown.

But remember, not everyone is dishonest. Just look at Ronda and Ed Grant -- an online dating success story with their own advice to finding the winner.

"Pay attention to what you read, and then pay attention to what you hear when you're talking to them," said Ed Grant. "If there's inconsistencies, that's a sure sign that something's up."

"You just really gotta take the first plunge, the first jump and just contact the person and take it from there, but just do it carefully," said Ronda Grant.

She also says that, when you go on a date, make sure to check in with your friends and if they don't hear from you by a certain time, have them call the police.