Referral Program "Store Credit" Taxable Income? Earned or Unearned? What if Never Redeemed?

I'm really having trouble finding clear income tax info on Referral Programs that don't give cash or other forms of commission payments directly, but rather the "commission" is tied to the purchase of their own products (or even other products) in the form of "store credit" or a discount on the specified product(s).

 

EXAMPLE:

I refer someone to Airtable (an online app I like) and when they sign up I get a $10 credit in my account to use on a paid Airtable plan.

*BUT*

I haven't yet redeemed any of the credits towards my own plan, so they're just sitting there unused.

 

My questions for this scenario are:

 

1. At any point would these credits be considered taxable income?
2. If yes, would they only be considered income if/when I actually REDEEM them, or, when I receive them regardless of redemption?
3. Would this income be EARNED or UNEARNED (i.e. count towards Roth IRA contribution)?
4. Would I file this on a schedule C, or another form?

 

Thanks in advance for any help! 😁