Deterding, S., Dixon, D., Khaled, R. and Nacke, L. (2011a) âFrom Game Design Elements to Gamefulness: Defining âGamificationââ, Envisioning Future Media Environments - Conference proceedings, MindTrekâ11, Tampere, pp. 9â15.
The payback method is a simple way to evaluate the number of years or months it takes to return the initial investment. The payback period is usually expressed in years. Start by calculating net cash flow for each year: net cash flow year one = cash inflow year one - cash outflow year one.
3. Spread the word. If the person thanks you and wants to repay you (that is, pay it back), let them know that what you'd really like is for them to pay it forwardâyou'd like them to do something nice for three people they don't know, and ask those three people to do something nice for three more people. If it makes the world a friendlier place, you succeeded! 2  The pay it forward concept was popularized with the book Pay It Forward by Catherine Ryan Hyde, which was later made into a movie with the same title, starring Helen Hunt, Haley Joel Osment, and Kevin Spacey.