Do you just want Facebook or do you want every social media service under the sun (Twitter, Pinterest, Reddit, Google+, LinkedIn, etc.). There are a number of smaller services which are like Facebook for a niche. Some countries have their own, especially China. Other major social networks like YouTube or Instagram aren't places to share general blog content.
Do you want to add a Like button or a Share button? People tend to Like things more than they Share. Likes across Facebook are aggregated/added