McDonald's Corp. is spending $100 million to revitalize sales and support franchisees in the wake of an E. coli outbreak. In a memo to employees and franchisees, McDonald's said the Big Mac burger with sliced onions is now back on menus nationwide, and the company is investing $35 million in marketing and advertising, according to a memo. In addition, McDonald's revealed that the company is spending $65 million on programs to support franchisees, such as rent and royalty deferrals.