Reporting Rebate Bonuses

I received a 1099-K from Paypal, most of this income was rebates for products, rendering the products free. I understand rebates themselves are not taxable; however, many of the rebates "overpaid" me for the products (e.g. I paid $30 for item, but I got a $40 rebate) as an incentive to try the product. Would the $10 profit be reportable income in this case? If so, would it be clearest to report this 1099-K under via "Other Miscellaneous Income"? Or might it be better to report it as Self-Employed under the job title "Household Product Tester" ? 

 

In case it helps, I believe it counts as self-employed income in my situation since I made a lot of money with this, rather than "hobby" income. 

 

Thank you!