Who most likely is the speaker?

Some of you have mentioned that you know our products better than those of our competitors. You, however, are still having difficulty selling them to clients. Therefore I will give you some advice.(90)First, speak clearly and avoid talking sloppy. Second, cover the points concisely. Third, survey your audience.(91)Have a good grasp of each client’s needs, and explain how our products will facilitate their work. Finally, don’t forget to call your client by name.(89)If there’s any way I can support you as your supervisor, please feel free to ask.