A logo is part of your brand but it's not your brand. One of the best examples is Apple. What does an apple have to do with digital devices? Nothing. But their brand is one of the best.

What makes a good logo?  Simple. Memorable. Timeless. Versatile. Appropriate. A good logo doesn't necessarily mean you have a good and well-thought-out brand strategy.

For me, their brand strategy would make or break my decision to work with certain companies. You know? their voice, how do they make me feel, are they user-centered? their value proposition, their brand perception, etc. 

Hope that helps, Katara. If you need any help, send me a message :)