Good examples are essential in a talk with impact. You explain your point, but the examples convince audience that it is valid.
Please look at this video to see a great illustration of this (the example starts at 1:19):
I would like to note two important points why this example is so effective. First, it is short and up to the point (the behaviour of the monkeys is clear even without the commentary; the video of the experiment is around 1 minute long). Then, it is easy to understand to everyone (all about emotions).
Note also the way to introduce the experiment: the speaker first describes briefly how it works. Then you actually see it. This explanation helps if you don’t see the details on the video (recognize the cocumber pieces from the grapes for example).
Do you have any other talks with great illustrations? Please share them in the comments!