Searching for love is no longer just a favorite subject for songs. It has also become a huge industry. Researchers say the online dating industry in the US earned 649 million dollars in 2006. They expect this number to increase to more than 9 million dollars by 2011. Experts say that the industry has grown because traditional social ties have weakened. Many young people leave behind a close community of friends and family to find work in bigger cities. People work longer hours, so they have less time to meet new people. This helps explain the popularity of online dating. Some estimates say120 thousand marriages a year result from matches made on the Internet. The dating industry has also been expanding in new ways. Many companies offer personalized services for finding the perfect mate. These companies are answering a large demand by single people. They are willing to invest their time and money to find love with carefully planned methods, instead of leaving love to chance. AskRomeo is a company in Virginia. It provides single people with advice on how to meet a person for the first time. Also in Virginia, the company True Life Partners provides a more costly and detailed dating service. The company hires a team of professional persons who help couples meet. But this level of service comes at a high price. Men pay thousands of dollars for the service. But women get to take part at no cost. There are lots of other costs linked to dating. And we wonder how the economic recession  has affected dating in the US. The author took AskRomeo and True Life Partners for examples to    _   .
emphasize the important role of the companies praise the two companies' good work show how the companies help expand the dating industry show the companies are the base of the industry