If you use social media just to meet people you can probably choose whatever route works best for you. Some offer more privacy than others. Some are more geared to lengthy interaction. Just trust your gut instinct.
If you are promoting a business, there is still no single right answer. I like Facebook because I sell crafts and need to use photos. Blogging seems to work well for me because I can write long posts that hold people's interests...although, admittedly, this isn't one of them.
And Twitter...well, I just can't explain Twitter. I can't post photos there without using links, but somehow I have the hang of using it. Whenever I type in LifeExpedition using an app or web site that gauges my twitter success or type of interaction, I get glowing reports. On one site, I was deemed within the top 2% most popular Tweeters. But truly, I cannot explain why I mesh well there. And more than that, I cannot say that it is boosting my business immensely. A little, yes. A lot, no.
And I feel a little sad for people who keep trying to get the hang of Twitter but repeatedly conclude that they either don't like it or don't get it. No biggie! It's a strange, giant cocktail party in which you hold conversations with hundreds of people at once. If you don't enjoy that premise, I hardly think there's anything wrong with you.