Find yourself humming "Matchmaker, Matchmaker, make me a match" just a little too often? Spark Networks (formerly MatchNet) can help. The company owns and operates a variety of online personal sites, including dating sites JDate.com (for Jewish singles), BlackSingles.com, and ChristianMingle.com. Spark Networks also operates websites in English, Hebrew, and French. Most revenue comes from subscriptions -- members pay a monthly fee to communicate with other users. (Customers are offered discounts for longer-term subscriptions.) In addition, the company offers offline events and opportunities for travel (such as cruises, dinners, speed dating, and mixers) designed to encourage live social interaction.