There are also some “alternative” sites that allow married people to find sexual partners (most famously, Ashley Madison.com) and others that enable specific sexual communities—such as heavy leather, sadomasochism, hook-ups, or polyamorous people—to find each other.

Pepper Schwartz, is the author and/or co-author of 22 books and stars in the hit A&E docuseries, Married at First Sight.

Perfect Match is for people seeking true love, a relationship, or marriage.

Hitchhikers, rocket scientists, even nuns probably do it, at least once. Then there are other dangers -- boredom, disillusionment, getting dumped, or simply getting taken.

If you think you do better in person than on the phone, then be brief on the phone, say why and suggest a coffee date.

It is not exactly clear when Internet dating began, but most observers credit an innovation created by Harvard students in the mid-1960s as the first computer matching service.

These were followed by niche sites, often organized around religious or ethnic homogamy, such as (for Jewish men and women), christiandate.com, catholicsingles.com, and Happy

Then comes the email saying, "I can't go through with this. There's serious stuff out there, like HIV and STDs, date rape, online stalkers."You're looking for a connection, someone you're physically attracted to -- who's physically attracted to you -- plus someone who doesn't make you feel bored from the get-go," Schwartz tells Web MD. "But don't let the love bug mesmerize you," says Paul Falzone, author of the book, Find the Right One and CEO of "The Right One"and "Together," two nationwide dating services.Then engage him in a discussion about why this was important to you and what you thought was at stake for the country.Or, if he is an art enthusiast and you are as well, talk about why art is so important to you and what museum shows you have enjoyed. Talk about real things that you both share -and if you have trouble expressing yourself on paper, have a friend help you craft the letter.