I have never taken up the exciting hobby of picking up bottle tops with a metal detector. However as a child I did find a " sainsburys" coin . Sainsburys was founded in 1869 and is now one of the Uk's largest retailers. Anyway the coin I found, was over a 100 years old and thinking myself rich, i asked my parents help me write a letter to sainsburys head office asking it's worth. I was informed by sainsburys that these coins were once used as promotional incentives but had no current value.
However as a young boy I was not deterred and insisted my dad purchase his petrol from Esso Petrol so I could collect my " Esso" coins of each member of the English World Cup squad in 1978.
Anyway thanks to this thread I have spent 3 hours hunting for that collection, and then having found it I looked up its value on Ebay. £ 20.00 + 2.80 p & p. :-(