Feedback is one of the best ways to improve when done properly.
One of the most important things when giving feedback is the moment you offer it. Some companies have feedback sessions once or twice a year. There are companies that launch certain services or products and wait for a few months before asking for feedback and then wait another few months to gather the results.
The sooner you offer or get feedback, the better. Think about dog training. As soon as it does something good, it gets rewarded. The same goes when you want to correct an inappropriate behavior. You have to punish it as soon as possible.
The same principle applies to feedback as well. If feedback is offered immediately after the action is done, the faster the action can be corrected or improved, while if a long time passes between the action and the feedback, the efficiency of the feedback is going to be very low.
The longer the time difference between action and feedback, the lower the efficiency.