The battle for point card supremacy in loyalty programs is hotting up across the country, causing consumers to express concern over privacy issues as a growing number of companies get in on the act.

Franchises have been running loyalty programs for more than a decade now, with Culture Convenience Club Co.'s T Card proving the most popular. Culture Convenience Club operates the nation's largest video rental store Tsutaya. Other members of the T Card group include convenience store operator Family Mart, gas station Eneos, family restaurant Skylark, drugstore Welsia and cellphone carrier Softbank. Customers can use their T Cards to accumulate "T Points" at any of the above locations. The points on such loyalty programs are typically equivalent to 0.5 to 1 percent of customer purchases. They can be used to reduce the cost of subsequent purchases at member shops.

The industry got a massive shot in the arm in July 2012 on the back of news that Culture Convenience Club had joined forces with web titan Yahoo Japan. Account holders at Yahoo Japan were merged with T Card holders, which despite some duplication increased the number of potential users in the program to 66 million. (At the moment, some 40 million people are members of the T Card program.)