As early as 1951, the Taiwanese government sought to address this problem by doing two things. First, it unified all receipt and invoicing platforms into a central system, which meant that all businesses which gave out receipts would automatically send the unique receipt numbers and invoice amounts to the government for tax reporting. (In fact, in Taiwan most people don’t need to hire accountants to do their taxes – the government can directly tell you how much you owe them or how much they should return to you).
But the second step is where we see true innovation. The Taiwanese government turned each receipt and invoice number into a lottery ticket for citizens to play. For every odd-numbered month, citizens can see if their receipt numbers match the winning prize. The first place would win the equivalent of $62,000 – about five years of salary for an average new college graduate, while the second place would win $6,200, with subordinate prizes scaling all the way down to $7.
Because of this “Uniform Invoice Lottery” system, consumers are now demanding receipts and invoices from businesses, preventing the business from evading taxes by exchanging cash under the table (or purchasing with Bitcoins). In addition, consumers are more likely to spend money.
Excerpt from: Actionable Gamification: Beyond Points, Badges and Leaderboards by Yu-kai Chou