The data shows that there are currently less than 2,000 group-buying websites in China, and there were 10,000 in the peak period last year. However, 40% of the websites were eliminated in less than a year. Analysts believe that after two years of competition, resources are gradually in the hands of a few hands, the market concentration will further increase, and only a few websites can survive. The surviving websites will gradually pick up the right to speak, and the gross profit will gradually rise. What does this text mainly introduce the group about buying industry? ['Competition.', 'Operational status.', 'Development trends.', 'Market prospects.']