- Am I likely to have to return my purchase?
- Am I using cash instead of credit/debit?
- Do I want to review what I purchased to make sure everything was the correct price and/or (if it's a bunch of items) that I got everything?
- Am I 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 I have an account which will let me 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.