MARKETWATCH - Dec 31 - For many singles, the holidays are the loneliest time of year and, in the New Year, the $3B dating industry sees a surge in users. Zoosk typically sees a 20% jump in users in the first two weeks of the year and eHarmony sees a similar increase in mobile registrations since the holidays. Grindr usually experiences a 30%-plus increase in users over the holiday season. Match.com and OKCupid also see an uptick between Christmas and Valentine's Day. "Many singles sit around the family dinner table during the holidays and think, 'Maybe it would be better to have a partner," says Mark Brooks, a dating-industry analyst and the editor of Online Personals Watch. "That's when they start hitting dating sites in droves and go on dates before the indigestion sets in."