1. It's a great learning experience and it will give you plenty of practice to improve your photography.
2. It will give you the opportunity to create a very high quality portfolio on a specific subject.
3. Inspiration, when the going gets tough and ideas are not flowing, you can always go back and work on your project.
4. A project gives you a starting point or framework that will allow you to expand your creativity.
5. Doing a personal project is all about you. You don't have to please anyone else, so let your creativity take you where you want to go.
6. Get Social! Engage with photography communities to discuss your work and get feedback.
7. Focus: spelling out a project over a certain amount of time will keep you on task.
8. Commitment: If you publish (in a community or on social media) your intentions to do a project, you will be much more motivated to complete it.
9. Putting a project out into the world will give you some credibility, which may help you to get help with your project. People on social media may suggest locations, models, props, etc...
10. Doing a project will show off your skills and commitment to creating quality work or a sustained period of time. This may help to draw fans and allow you to sell images or to book more jobs. Just remember to show off the kind of work you want to do or sell.
I hope to see you in the Create Challenge during 2017, it's completely free and you can start the challenge at any time.