'cause i've nothing better to do (just don't tell my boss), I have been researching this, and below is the best description, however, another site (Oxford Dictionary) quotes it as a Scottish dialect word for cobbler. Therefore, SNOB as a cobbler came before SNOB as a person.
1781, "a shoemaker, a shoemaker's apprentice," of unknown origin. It came to be used in Cambridge University slang c.1796 for "townsman, local merchant," and by 1831 it was being used for "person of the ordinary or lower classes." Meaning "person who vulgarly apes his social superiors" arose 1843, popularized 1848 by William Thackeray's "Book of Snobs." The meaning later broadened to include those who insist on their gentility, in addition to those who merely aspire to it, and by 1911 had its main modern sense of "one who despises those considered inferior in rank, attainment, or taste."