What numbers Tapastic has, they are keeping pretty close to the vest, which is why we have to use SimilarWeb as a round about way of figuring things out. So that everyone knows, not sharing numbers is a VERY common practice in the publishing industry and most publishers guard their data fiercely. Since traffic is their livelihood, and image is everything, putting out specific traffic data is like opening your wallet up for other publishers to put their fingers into. If your traffic is less than expected, advertisers are going to spend less, if your traffic is higher than expected, someone is going to try to create a similar product to steal part of your pie.
What we'd really like to have on our dashboard is something similar to what Kickstarter offers where you can see where your traffic is coming from and how many of them "pledge" or in our case "subscribe". It would definitely help us figure out what marketing is the most effective for our series (f.e. Facebook vs. Twitter). Having just concluded a sizable Project Wonderful ad campaign, better data would help us figure out if to renew it or not. Not having adequate tools means a lot of guesswork for creators.