Social media for different sites

I am going to start up two affiliate sites that are completely different niches. Do I need to have twitter and facebook accounts for each? And when I run more niches, how do I keep up with all the different social media accounts?:(
thanks
judi

Judi,
You don't have to have Twitter and Facebook for all niche affiliate sites. But if that is what you're thinking of doing, yes you would need separate ones for each different niche. As for keeping up with various accounts, you could use the paid version of Hootsuite.com

If you use one account for each niche you will look more credible

Check out TweetDeck, their free desktop version will handle multiple twitter accounts. Multiple Facebook accounts is more difficult. I would suggest you use something like LastPass or KeePass to keep your passwords safe.