Search engine marketing continues to be a central part of online advertising budgets, as well as the main driver of online sales. At the same time, the percentage of advertising spending is directly proportional to the percentage of online sales generated by four out of six marketing initiatives. This report summarizes a series of useful online marketing benchmarks that assist online retailers in determining how to ensure that every dollar of their online advertising budget produces healthy sales returns. These benchmarks are based on a recent survey of 206 US online retailers that includes questions on the topic of online marketing. In this report, we also examine multiple ways in which online retailers achieve advertising cost efficiencies by advertising budget size and product categories.