I believe that Sonic is a great marketer. Not because of their television spots, which have been met with mixed reviews. Not because of their outdoor ads either, although I absolutely love them. What I think they do really well, is what they do really well.
That is to say that they are not trying to be something that they're not. But, when they do make a change, or product introduction, they do it within the parameters of their brand.They don't try to create a personality for every new thing that they do- they introduce it within their own brand personality. And, if you are familiar with their brand, you readily accept this change or introduction.
That's a benefit of branding, and generally smart marketing. I believe that Sonic is so successful because they are a marketing organization that happens to sell food. I have no inside information about Sonic, and we've never done any work for them. But, it appears to me that marketing drives a good many of their decisions. Smart marketing at that. Equally as impressive is their ability to act quickly. When reality TV hit, they developed the current campaign. Philly cheesesteak fad? Got 'em. Wraps? Yep. Breakfast craze? They opened for it (and serve it all day). All served quickly, consistent to taste, and with a smile. I'm not sure I like Sonic's food any better than any other quick- service brand. But I like Sonic quite a bit better. Better marketing sure tastes good.