you have to think that most providers may deploy servers within 24 to 48 hrs, but will say give 72hrs (just like domain registrations), but a lot of server providers will ask the buyer to provide ID etc. which will add to a delay.
I once had someone order a VPS which the system will automatically ask them to sent in a copy of photo ID and residential ID and then once we check this we will either refund or deploy server. He contacted us within 10 minutes in an aggressive manner demanding to know why he had not received the server details. I told him to read the email he received and follow its instruction to send in the required ID. he stated he never received any email ( strange as i had the email receipt to show it was not just received, but opened). i told him this and he got more aggressive, so i told him to make things easier i will cancel the order, refund and he can go elsewhere.