Cave is best known for beginning the Gentleman's Magazine, the first of its kind, in 1731. It originated as a digest of London newspapers and periodicals for country customers (reflected in Cave's editorial pseudonym, Sylvanus Urban), but proceeded to expand and thrive. "At 6d. and seven octavo half-sheets it truly gave ‘more in quantity, and greater variety, than any Book of the kind and price’ (Bavius)." In 1732, the London Magazine became its primary competitor. Cave had a number of business ventures, but his most successful ones were in the periodical milieu; he generally sought low-cost, low-risk publications intended for the masses. Lucrative publications included Johnson's Rambler (1750-2), Hawkesworth's Adventurer (1752-4), and 220 of SJ's works. The DNB attributes GM's success to Cave's innovation, distribution advantages with the provincial book trade attained through Cave's connections with the Post Office, and editorial policy. While GM originally focused on newspaper extracts, commercial information, and parliamentary reports, accusations of 'literary piracy' compelled Cave to publish more original work, particularly poetry, and to 'cultivate a wide circle of customer-correspondents.' The magazine launched novice poets, including SJ, Carter, Akenside, and Hawkesworth. It also contained both licensed and unlicened extracts from well-known, seasoned writers such as Thomson and Savage. Eight poetry competitions throughout the 1730s provided GM with publicity and copy for the columns; some talented contributors became editorial assistants as a result. The DNB notes some of the criticisms Cave received: "The uneven quality of this verse often exposed the magazine to censure from those indifferent to the realities of running a contributory mass circulation miscellany. Nor did they appreciate the emergence of a new kind of mercantile patronage, where an educated provincial middle class could achieve literary visibility in the face of a trade dominated by metropolitan booksellers." In the late 1730s, with a circulation of 8,000-10,000, GM focused more on political/military reports as opposed to poetry. Cave died with "a personal fortune of of £8708, including £3000 invested in the Gentleman's Magazine, of which he was sole owner."