No need to market. In most countries Pokemon Go was already popular but app was not officially available in Play Store/App Store yet. So millions of people searched stores for Pokemon Go and downloaded chat, tutorial and apps like GoSnaps instead..
In the UK I looked for the app, saw a load of fakers and avoided them but I could see others [children particularly] installing a lot of those apps just trying to find the right thing (instead I installed Ingress to get an idea of how it might all work).
Seems like this sort of inability to find trademarked apps in the app-store makes it look far lower quality over all.
What would have been ideal as a user would be a "get Pokemon Go when available" that would have allowed Niantic to roll it out to my Android device and manage downloads a bit more progressively.