The 20-second viral kicks off the competition, which is open until November 15, with MC Hammer speaking directly to camera in a kitchen. It will be followed by a national TV campaign from ad agency Euro RSCG.
He says: ""It's time to take that gold, you don't need the crown jewels, it's time to take that gold and get it sold. Don't forget to tell us who you'd like to see in our next UK commercial."
If the celebrity the company chooses is one that a member of the public has nominated then one person will win "the chance to have tea with MC Hammer and the yet-to-be determined celebrity".
Cash4Gold is attempting to get as well-known in the UK as it has become in the US, where it has run a number of memorable TV campaigns. This has helped it forge ahead of a number of companies trying to capitalise on the trend for trading in used jewellery and other valuable items for hard cash during the recession.
In the US earlier this year, Cash4Gold ran a 60-second TV spot during the Super Bowl, featuring MC Hammer and 'Tonight Show' host Ed McMahon.
Since then it has attempted to raise awareness of its service in the UK through a series of corny TV ads featuring testimonials from members of the public who have traded their gold for cash.
A recent Cash4Gold UK TV campaign: