I have no recommendations for where to get traffic data. I've never really tried to before.

I don't even really know how much traffic PeakD gets, but something tells me that under new ownership Steemit Inc. is going to leverage massive resouces to pull users specifically to Steemit.com over any other blockchain interface.

It would be interesting to see the relative shares of each interface for each blockchain, perhaps in a pie chart. I'd estimate that for Steem Steemit.com would have the largest slice, maybe even a majority, alongside a bunch of tiny slivers for each other interface. Maybe we'd see more equal slices for Hive, and I wonder what the plurality would turn out to be.