A posting by the NYC law firm Frankfurt Kurnit illustrates the disclosures that companies must do when customers provide reviews of them. In one case, a company offered a $25 Visa card sweepstakes as an incentive to its newsletter subscribers to write product reviews. The conditions of entry mandated that the reviews indicated they were part of the sweepstakes call to action and were tagged on the company’s site as such. The process was challenged by a competitor before NAD, an advertising self-regulatory body, but the company’s actions were acceptable. The takeaway: Disclosures of any incentives to write reviews must be clear and conspicuous.