I wonder how the Google Play store compares to Amazon or Humble Bundle. From the Humble Mobile Bundles and Amazon give away's, I've bought probably about 5 apps

I wonder how the Google Play store compares to Amazon or Humble Bundle. From the Humble Mobile Bundles and Amazon give away's, I've bought probably about 5 apps from Google Play, yet I have over 60 from humble and 20 from amazon.