When asked about your biggest strength, explain about a skill that will help the company grow, e.g. being able to interact easily. This strength of yours would help the company get a lot of customers.

Always remember, no one is perfect. But you can always try to work on your weaknesses. Before satisfying anyone else, you should feel satisfied with your work yourself. You should know your weaknesses and the areas where you lag behind. And, thus, work on them.