Posting to one or more social networks can improve your visibility on the web and increase your chances of being found by searches. It also gives you essentially a news outlet where current activity can always be viewed.
However, once you head down that road you have to remain committed to making regular updates of some kind. New images, travels, observations, whatever... something to demonstrate active and ongoing involvement. If you let your social network go stale, you'll lose your audience.
"He was a wise man who invented beer. -- Plato"