Social networks are all over the place, they are places to meet and exchange information - can you have too many social networks ?
My answer is NO.
If you want to meet people and build friendships AND business you need to go looking for others that are interested in that kind of lifestyle too - it doesn't suit everyone to mix their on-line lives up like this - BUT I think this is the way for people on a small budget to go.
Most social networking let you set up a profile with all your business stuff on - keep all your business stuff on your profile, then go out a chat in the networks, find out where it is okay to post adverts/blogverts etc.
I will put other people's social niche builder websites here when I find them.
My version is here ===> www.totallyu.co.uk my niche is Coffee - this site is about instant coffee and 'no fuss' coffees of all sorts I've tried or intend to try.
You can buy a copy of the Script here (on the OTO page) the web tools are a free bonus - if you already have a copy of social niche builder just join up for the freebies and you can access the SNB videos - in other words - you can make some cash via their affiliate program if you can't afford to set up your own - and you get free stuff to give to your downline or optin list.
Note: I am learning how to use this little script (social niche builder)it's a bit old but has potential to be customized - I figured out the captcha problem - so contact me if you need that info. (or look in google like I did!)