PHILADELPHIA (CBS) -- You've probably heard of shrinkflation and greedflation before.Tips, a staple of the service industry, are now extending far beyond."It's a relatively new phenomenon," Dipayan Biswas, marketing and business professor at the University of South Florida, said.He says this new tipping trend started with the boom of digital kiosks, then the pandemic "added flow to that fire," plus inflation and more businesses allowing tips to make jobs more lucrative at your expense.Farley, an etiquette expert said, "the very concept of a tip is that we are rewarding a service employee who's being paid less than minimum wage.""