If you have multiple Twitter accounts and/or Facebook fan pages, you have probably cross-posted content or retweeted yourself more than once already... That may be fine but at some level you also run the risk of annoy your followers with too many duplicates and you will lose some of those hardly aquired fans & followers...
Of course it's up to you to decide how you want to address your followers and fans but I recommend you really think it through before you spam them away by mistake... Here are my own rules of thumb on the matter:
- Your product/service specific accounts should talk only about that product, not about your personal life or rants (unless you *are* the product!)
- You can retweet some major product news/milestones on your personal profile but you should avoid RTing personal stuff on your product profiles.
- Use the "selective tweets" app on Facebook in order to not overpipe stuff from twitter to FB
- Make sure you never have duplicate content/status updates/RTs on facebook. Noise is more commonly "accepted" on Twitter than on Facebook.
Finally, remember that overloading your followers with promos will give good results in the short term but it will also burn your followers out! And in many markets, you cannot replace your current followers with new ones of equal quality indefinitely...