When it comes to love, Kathleen Hanover is searching for a needle in a haystack. So to find Mr. Right, she has profiles on at least five online dating sites.

Hanover, who owns a marketing business, figured it's simple math.

"You have to have a big pool of leads to find the percentage who might feel right," said Hanover, 43, of Dayton, Ohio. "I'm looking for a very specific kind of man."

With 1,400 online dating sites, according to research firm Hitwise, many singles are finding it easy to cast a wide net, posting profiles on multiple sites in the hopes of reeling in the one.

Melissa Galt, an interior designer and motivational speaker in Atlanta, was on four sites at once and compared it to having a second full-time job. One site she used was about "quantity and not necessarily quality." Another was better suited to one-night stands.

She subscribed to eHarmony multiple times, but had no luck there and didn't fare much better at Match, where she struck out enough that the site was willing to give her six free months. Since then, Galt has gone out on two dates with someone from Match and said so far, so good.

Neither eHarmony nor Match, two of the leading online dating sites, capture information about how many of their members are on other sites. Match has 15 million active members worldwide. EHarmony has more than 20 million registered users around the world.

Markus Frind, CEO of the free dating site Plentyoffish estimates 15 per cent of the people in the United States who are active on his site are members of other, paid dating sites. About 900,000 people in the North America and the United Kingdom log on each day.

It makes sense to post profiles on more than one site, according to Mark Brooks, editor of Online Personals Watch and an Internet dating consultant.

He compares serial online dating to bar-and nightclub-hopping. Someone may go to a wine bar one night and a "Cheers" bar another night. He said people generally settle on one main site and a smaller niche site.

Jordanna Petkun, 30, a business owner in Half Moon Bay, Calif., said JDate, a site for Jewish singles, seemed to run out of potential matches. So she signed up for OKCupid, but she didn't want to cancel JDate, because "what if the right guy comes along tomorrow?"

Some relationship experts aren't so sure that signing up for multiple sites brings better luck in love.

Michael Somerville, host of the upcoming dating series "Wingman," on the Fine Living Network, wonders how people can genuinely give the time and attention to a potential match on eight different dating sites. If you really want to meet the right person online, you need to work at it, he said.

"I have seen daters who spend more time checking their dating sites than they do dating," said Nicholas Aretakis, author of "Ditching Mr. Wrong: How to End a Bad Relationship and Find Mr. Right."

Jess McCann, a dating coach and author who was once on three sites at the same time, said she was cutting and pasting generic responses to emails for a while. She had two folders: one for the men she wanted to meet and another for the ones she was so-so about. If one of the top prospects disappeared, she bumped up one from the other folder.

She has since met her match - but not online.

Tricia Dodson, 47, of Murrieta, Calif., who has been on four or more sites at the same time, said she printed out the profiles of the men she communicated with and wrote detailed notes on them, such as hobbies, career and "cute things he said."

"This isn't a fail-proof system," said Dodson, who wrote a book about dating. "At one time, I was emailing and talking to six different men via phone and there was a time or two that I got them mixed up."

So just how much is too much?

Aretakis recommends singles sign up for one general site, a second specific site and a third niche dating site. So for example, someone who is Jewish and loves to fish might be on Match, JDate, and Single Fishing Enthusiasts on the Net.

But it's better to be on one site proactively than three passively, said Nancy Slotnick, founder of the love-life management site Cablight.com. She recommends that singles log on and email 10 people a week. Of the 15 hours a week Slotnick recommends spending on finding a mate, she suggests spending no more than three hours on online dating.

After all, there is a real world out there.

Hanover has no time for that. In fact, she's so short on time that in some of her online profiles, she directs potential suitors to her personal website, www.myheroquest.com where she asks prospects to give her five first dates' worth of details about who they are and what they want in a relationship.

"I honestly don't have time or the patience for long, drawn-out, get-to-know-you chit-chat and casual dating," she writes on the home page, adding "frankly, I'd rather get some extra sleep!"