As an R.E.M.-Centric shareholder in REMChronicle, the idea of Songkick is fascinating as it's use of data-driven methods attempt to find for you concerts that you would enjoy. If you are like me and wrap a couple of headphones around your ears and allow last.fm to do its thing, you will be provided with a slew of concert events as well as create an official site for every possible concert event in the history of music.
As if that is it's primary goal, Songkick has a long way to go, whether they will try to be the "Wiki" of concert data; if fans decide to flock in droves in order to do just that. My couple of moments were reviewing the concert data for R.E.M. It would seem that of course the busy workers at Songkick visited the Chronicle as well as remtimeline to acquire the full-fledged concert history of R.E.M., missing of course the most vital component, the songs! I could imagine that such an endeavor would take a long time, considering how much time I spent data-entering this information-most likely sitting in my boxers listening to music as I dutifully spent that time making sure that every setlist was entered.
I have to look at this from two different perspectives. As a music fan I find it fascinating. If the site gathers enough fans that find it's pages attractive then I would surely deem it as a source.