• Are you likely to have to return your purchase?
• Are you using cash instead of credit/debit?
• Do you want to review what you purchased to make sure everything was the correct price and/or (if it’s a bunch of items) that you got everything?
• Are you being reimbursed/reimbursing someone?
• Am I in a shopping mall where I’ll be bringing this merchandise into other stores with similar offerings?

if any of the above factors are true:

• Do you have an account which will let you receive a digital receipt instead?
• If not, then yes.

If none of the above factors are true: No. At that point to me it’s just a waste of receipt paper and my time.