So it's smart for Github to build tools that lower the bar for a) understanding git, and b) using git's more powerful features.
Useful metrics would be things like the percentage of users who use the pull request flow, use it with at least one comment per pull request, have pull requests that get revised, etc. etc.
I'd guess that part of the growth potential driving Github's valuation is the notion that git's power features add significant productivity/value and that github is uniquely positioned to let a significantly large number of developers and teams make optimal use of those features for development and collaboration.
But then you start talking about pull requests, which are not a feature of git. They are specific to github (e.g. try finding a PR comment in the git repo).
Does the new tool help with advanced git stuff, or does it just serve the github workflow?
At this point I don't think the tool does all that much advanced stuff, but the focus appears to be on understanding git at a level required to understand the more advanced features... so actually more focused on the semantics of git than on specific workflows.
Actually, they are, though github pull requests appear to be designed in a way that is not interoperable with the native feature.
 = http://stackoverflow.com/questions/9630774/how-to-make-pull-...
About which powerful features are you talking about, does anyone have a link with some more in depth informations?
Even the command line git itself is really nice because it gives you the current condition of your repo and suggestion on what you can do next. You have changes, if you want to commit use this command or if you want to add use this command.