We definitely understand that some of our users prefer not to use the social sharing features of our app ; hence we added the capability to turn those off, either temporarily with the use of the "social-sharing" switch at the top of the interface --or-- permanently via the preference dialog that you can find in the top left menu.
My mental model of sharing (and I'd bet it's shared by many others as well) is that there needs to be an explicit "sharing action" taken. I should know exactly what happens when I do something - I don't on your site. As a result, I never get to the "aha" moment because I'm afraid to click on anything.
Seamless sharing is also a "band-aid." It gets users sharing your app at the beginning but there's definitely some users who are turned off by it.
So although this is where a lot of our referral traffic comes from at the moment there are undoubtedly better ways to do this and we're working on it. These are early iterations on the product and we'll be circling back very soon.