My grandmother just friended me on Facebook. So, either hell has frozen over, or social media has truly permeated every aspect of life. This multi-generational Zeitgeist is huge and companies are caching in. The best part is it is cheap and easy enough for even the smallest website to take advantage of.
The lazy approach to social media marketing is to install a bunch of plugins, which is the reason why some websites look like a McDonalds playground of colors and floating boxes.