Just watched a video from Google's 2015 testing conference called Large-scale Automated Visual Testing. Incredibly insightful talk by a cofounder of Applitools, a SaaS provider for visual diff testing.
I heard of Applitools before when I was researching various visual diff tools for my team at work, and I was initially wary that the talk would be an extended informercial of Applitools' product. My concern was quickly proven wrong. It's an incredibly informative talk filled with numerous examples and demos to demonstrate various tips he has for doing visual testing in an efficient and effective manner. I was actually blown away by the demos of Applitools and how effective they were at identifying "structural changes", that is substantive changes to a website / app, and being able to ignore minor differences between browsers or dynamic content that changes (e.g. article blurbs that change each day).
I'm looking forward to trying out the free plan and seeing if we can incorporate Applitools into our team's continuous delivery workflow.