The best products and businesses solve problems otherwise left unaddressed. Customers and owners win as a result. Vidalias onions provide this week’s example of a business model innovation with the potential to solve an important problem. Any mother can speak eloquently about the challenges of getting her child to eat healthy foods, with vegetables the most daunting. Yet, sales of Vidalias onions are way ahead of last year’s numbers – because of kids. A savvy campaign involving Shrek, a beloved ogre staring in Dreamworks’ films of the same name, deserves the credit. The onions are displayed with pictures and a giant blow-up of Shrek in the grocery store, complete with recipes like Swampy Joes. Kids, according to the June 28, 2010 Wall Street Journal, are clamoring for Moms to buy Vidalias onions and cook the meals that Shrek and his friends enjoy. What’s…