From Wikipedia:
http://en.wikipedia.org/wiki/California_Gold_Rush#ProfitsEmphasis mine.
Recent scholarship confirms that merchants made far more money than miners during the Gold Rush.[90][91] The wealthiest man in California during the early years of the rush was Samuel Brannan, the tireless self-promoter, shopkeeper and newspaper publisher.[92] Brannan opened the first supply stores in Sacramento, Coloma, and other spots in the gold fields. Just as the rush began he purchased all the prospecting supplies available in San Francisco and re-sold them at a substantial profit.[92] However, some gold-seekers too made substantial money. For example, within a few months in 1848, one small group of prospectors working on the Feather River retrieved a sum of gold worth more than $3 million by 2010 prices.[93]
On average, half the gold-seekers made a modest profit, after taking all expenses into account. Most, however, especially those arriving later, made little or wound up losing money.[94] Similarly, many unlucky merchants set up in settlements which disappeared, or which succumbed to one of the calamitous fires that swept the towns that sprang up. By contrast, a businessman who went on to great success was Levi Strauss, who first began selling denim overalls in San Francisco in 1853.[95]
Other businessmen, through good fortune and hard work, reaped great rewards in retail, shipping, entertainment, lodging,[96] or transportation.[97] Boardinghouses, food preparation, sewing, and laundry were highly profitable businesses often run by women (married, single, or widowed) who realized men would pay well for a service done by a woman. Brothels also brought in large profits, especially when combined with saloons and gaming houses.[98]
By 1855, the economic climate had changed dramatically. Gold could be retrieved profitably from the goldfields only by medium to large groups of workers, either in partnerships or as employees. By the mid-1850s, it was the owners of these gold-mining companies who made the money. Also, the population and economy of California had become large and diverse enough that money could be made in a wide variety of conventional businesses.[99]
The parallels... are obvious.