I've heard that non-organic foods have certain toxins that harm the body. Those are referred to in the previous posts regarding pesticides, farming chemicals, etc. Large corporations produce such products, As far as organic foods is concerned, the smaller farms, locally owned, which do not use the pesticides, chemicals, etc are produced by them.
For some, organic foods is trendy. Think upper scale grocery stores like Whole Foods/Freshfields/Harris Teeter/etc. But in short, if I had a choice, I'd go with organic to help out the smaller farms. Competition for consumers is always good.