Leon Bryan, 27, grabbed the 63-year-old customer in a headlock before throwing him to the floor several times until he could no longer get up, Nottingham Crown Court was told.
The violent five-minute-long attack, which left the victim with cuts and bruises, happened at Premier Stores on Ruffold Walk, Bulwell, on Saturday 28 May.
Bryan, of Bethnal Walk, Bulwell, left the store but returned, throwing the victim to the floor again, before trying to wrench a pouch of tobacco from his hand.
He wasn’t able to steal the man’s tobacco but he was seen to grab a pouch of tobacco from the shop counter and leave.
The entire unprovoked and sustained incident was caught on clear CCTV footage, the court heard, with the victim not even defending himself from Bryan’s attacks.
Bryan, who admitted robbery, was sentenced at Nottingham Crown Court on Friday, October 7 after pleading guilty on 12 August.
As well as his eight-year jail term he was ordered to pay a £170 victim surcharge.
Detective Constable Charlotte Rolling said: “This was a completely unprovoked and extremely violent and sustained attack on an elderly member of the public who was just buying a few bits and bobs from his local shop.
“What Bryan subjected this man to was horrifying. The bravery of the victim, who has shown courage both during the incident and throughout the course of the investigation, should be praised.
“The sentence of eight years imprisonment adequately reflects the severity and violent nature of the crime.”