Of course, I clicked on "Get this widget!" first, because I have widgets on the brain lately. That made me wonder whether the ad was really that effective.
I quickly realized that it was more effective than a "standard" ad. Get some good creative in that widget, and you have enabled it to not only be clickable for more information on your brand, product or offer, but you've also turned the ad itself into a viral marketing mechanism.
Now how much would you pay!