How to fill out income from Rewards program

Hobby or business has been a long-standing question.  Part of it is whether you are holding yourself out in that activity as a business.

From IRS

https://www.irs.gov/newsroom/earning-side-income-is-it-a-hobby-or-a-business

Here are nine things taxpayer must consider when determining if an activity is a hobby or a business:

• Whether the activity is carried out in a businesslike manner and the taxpayer maintains complete and accurate books and records.
   
• Whether the time and effort the taxpayer puts into the activity show they intend to make it profitable.
   
• Whether they depend on income from the activity for their livelihood.
   
• Whether any losses are due to circumstances beyond the taxpayer's control or are normal for the startup phase of their type of business.
   
• Whether they change methods of operation to improve profitability.
   
• Whether the taxpayer and their advisors have the knowledge needed to carry out the activity as a successful business.
   
• Whether the taxpayer was successful in making a profit in similar activities in the past.
   
• Whether the activity makes a profit in some years and how much profit it makes.
   
• Whether the taxpayers can expect to make a future profit from the appreciation of the assets used in the activity.

In this case, what expenses do you have in this?  If simply referring people to a business to earn "rewards" doesn't lend itself to any expenses.  If you classify it as a business, you would need to file Sch C and then end up paying self-employment tax on the profit.  Expenses would be deducted on Sch C as a business.  Expenses for a hobby are deducted on Sch A and are limited.