My Take
I like the brain pop videos. They are a great way to address curriculuar content, are engaging for students and can be the launching pad to further activities and class discussions. The only drawback is the cost.
How I Use It
I use it to launch at topic of discussion or a project. For example, after watching the healthy eating videos (you can have them watch as a small group or as a whole class) we then had discussions, posed questions, and watched the video again to see if we could answer our questions about healthy eating. Students were then able to create a powerpoint with the information they learned. A much more interactive way to learn about healthy eating in the higher grades and not too time consuming for teacher set up.