Subscription models are lucrative. While Microsoft rakes in the dough with Xbox Live, Sony has been trying to entice PS3 gamers to invest in PlayStation Plus. A recent survey shows how Sony is playing with the formula, seeing what would generate the most interest in the premium PSN service.

For example, the survey quizzes interest in offering "new Blu-ray games" with the subscription, or offering free access to Call of Duty Elite with a Plus membership.

Sony's survey shows that they are considering changing nearly every aspect of the program, from the number of games offered to members to how new offered games will be. For example, one variation of the program will offer 70 games per year, including 10 "full Blu-ray games."

Pricing is also something the company is willing to change. Right now, Plus is offered for $50 annually. However, Sony is also considering a $60 annual option--as well as the possibility of offering monthly plans.

While the inclusion of Call of Duty Elite is far from assured, it shows that Sony is actively considering it. Should PlayStation Plus include the service, it would be seen as a tremendous value, given Elite already commands a $60 price tag. A move like that would certainly sway many gamers away from Xbox 360 as the Call of Duty system-of-choice.

Sony refused to comment directly on the survey, telling IGN: "We have nothing specific to announce at this time, but PlayStation Plus continues to delight gamers with free games, huge discounts and exclusive gaming features that can't be found on other platforms."