Not why you need it.

Command the tasks and responsibilities in your current role, then start solving the problems that your soon-to-be self would be working on.

Show you’re invested in the company.

Conduct background research to determine your market value. 

• Demonstrate that you have taken on additional responsibilities and provide specific details about your accomplishments. 
• Share examples of projects you have completed and how they’ve positively impacted the business. Was there an increase in revenue? Did you save a cust...

... in which you are asking for something almost always go better if you've rehearsed in advance and have considered the many possible responses that you'll get to each of your requests, and how you'll address these responses. 

Consistently exceed expectations in terms of your current role and job responsibilities. Take on more than expected, and manage these projects as well as your more senior colleagues.