on the twitter front, is there a good way to get secondary influencers that are following a primary influencer and interact with that influencer on a regular basis?
You can achieve this for a few accounts with the Twitter API, but due to API limits, it is tough to get it done at scale and make a product out of it. There are creative ways of achieving this, though.
Point in case: take a look at how Nuzzle works for Twitter accounts. It is very close to what you are asking for.
thanks for suggesting Nuzzle, I had not heard of this before.