Auction sites, like garage sales, flea markets, classified advertisements and other independent sales venues, sometimes draw criminals wishing to sell stolen products, but for law enforcement organizations, finding stolen goods offered online is sometimes easier than more traditional detection methods.

Some criticism is leveled at online auction websites for uneven representation of items offered for sale. Descriptions may omit important information, and photos may not be adequate. Potential bidders can typically protect themselves by reading the text, studying photographs and asking questions of the seller before bidding. Studies show that a large proportion of unsatisfactory online purchase experiences are the result of careless consumerism.

In Australia large retailers have lobbied Congress to require online auction sites to share private sales information about sellers, citing potential illegalities. Within the online auction community this is commonly viewed as an attempt at unfair market protection and trade restraint. Reduced overhead sometimes enables independent online sellers to offer goods at lower prices than large retailers.

Online auction selling has attracted millions of laid-off workers, as well as the disabled, parents of young children, retirees, pensioners and others that are unable to find employment in the mainstream workforce.