Thank you for reviewing Twitalyzer as part of this post. I want to expand on a couple of points that you made.

Since our team comes from the web analytics space, we appreciate your reference to how we all collect, define and calculate Influence in a similar manner to the WA vendors do with measures like Unique Visitors and Visits. That said, I should note that with our 2.0 release last month, we made some changes to our metrics. Impact has supplanted what was previously calculated as Influence. You can see here what are metrics and measures mean: http://www.twitalyzer.com/help.asp#definitions

Regarding “more topical or categorical influential data” Twitalyzer has that and then some. Start with the Benchmark report as an example. You can filter by location and/or Tag. Tags are attributes that are either auto-discovered by our system (via hashtags) or manually added by users. For example, I may want to see who are the most influential people on Twitter using #measure, I will see this http://www.twitalyzer.com/list.asp?u=twitalyzer&f=&l=&t=measure I can drill down to just people in Portland – http://www.twitalyzer.com/list.asp?u=twitalyzer&f=&l=Portland,+OR&t=measure

Of course that is just one of many ways organizations and individuals can sort and filter through our data.

– Jeff