The Summit label was named after the monetary-themed card game Sum-it, invented by the father of Alternative boss Roger Hulley in the 1930s. Initially launched as a full-price label, the mixed success of its first release - Spectrum graphics package Art Master - convinced Roger Hulley that big boxes and price tags weren't the way to go at that stage and the Summit label was promptly converted to a budget label.
Incidentally, the label was launched in mid-1988 when Summit ran a competition in the games magazines to win a collection of mint condition pre-decimilisation coins. The prize was won by Alan Clark from Camberwell, UK after he was the first entry drawn that correctly converted the £2.99 price of Summit's 8-bit titles into pre-decimal imperial currency.
[Sources: Commodore Disk User, Vol. 2 No. 3 (March 89, p4) and Your Commodore, (Issue 54, March 89, p8), courtesy of the Internet Archive; Retro Gamer (Issue 107, pp50-55)]