Subway's Message: Eat Fresh
The message is trying to promote healthy eating by saying Subway's products are fresh and their competitor's products are not.
The good: Subway's message of "Eat Fresh" sums up what Subway is about: providing fresh, healthy foods to customers.
The bad: It's misleading. "Eat Fresh" implies that their food is fresh and not processed, when in reality their meats and cheeses are processed. Plus, they are a fast food restaurant so there's no way that they could provide fresh foods in a timely manner and in large quantities.
In conclusion: Even though the slogan is misleading, it's effective overall because it promotes healthier eating and gets to the core of what Subway is all about. Plus, it links "Subway" with "fresh" which is definitely a good thing.
Publics: The message has a target public of those who are watching their weight, want to eat healthy, and care about eating fresh foods. Basically, the "health conscious" people.