It’s interesting. Year over year our clients’ open and click thru rates have decreased for their emails asking for reviews after purchase, but response rate for reviews has slightly increased. We see this trend across both retailers and brands. I believe this is tied to exactly what several commenters have mentioned: ease of review submission. Mobile clearly plays a crucial role in this, and retailers would do well to optimize for this experience. The most successful retailers I have seen at collecting content embrace all of their touch points in order to actively build and cultivate a community of advocates that are invested in the experience the retailer provides. Once that community is built, campaigns such as sweepstakes, sampling programs, and altruistic calls to action have maximum impact.