said by NOCMan:What Verizon eliminated is the return receipt you would get from using vtext.com. I'm not aware of any phone that did delivery receipts via the handset itself. So it's a really small subset of customers and probably more spammers using that feature than anything.
Every verizon handset that can text gets delivery confirmations in the form of a checkmark next to the envelope in your Sent box. You can click the message and view details to see exactly when it was delivered. Windows Mobile phones get them in the form of another text message saying "Your message to [phone number] was delivered."