It's all in what you want to get out of it, imo. I use social websites as a tool for my relationships, whether it's meeting people exclusively on-line who I might have something in common with; like here or a turtle owners forum I belong to. I get advice, share stories and connect intellectually and personality-wise.
I use Facebook to keep up with my kids who no longer live at home and other family members. I also have reconnected with a dear friend from elementary/jr high on Facebook. We live an hour apart now and we meet one Saturday a month and spend the day together just us, no kids, no spouses.
On-line sites have the ease of anomynity and no commitment. You can hang out as long as you like and then slip away quietly with no excuses or awkward avoidances. I fall off the grid here every so often because of health issues or time allowances or phases of the moon.
If you are wanting to meet people that you will follow-up with and meet person-to-person, nc.com isn't the ideal solution. There are websites that are specifically aimed at that goal. You could also look into joining into community activities, clubs, and groups that interest you. We like you here too