Which Google user would want to pay for ads about things you cant buy ('noshop')?
Oh wait, you meant Google _product_. You want Google to cater to its product needs by sacrificing own money making potential and limiting its actual users.
Google already tries to infer whether a user is shopping or seeking information and serve results accordingly. If I search for "managed vs unmanaged switch" or "massage ball usage", I do not see any ads.
All I'm saying is that Google should consider allowing users to explicitly state their intent, since some queries ("massage ball" and "managed switch") are ambiguous and so the intent cannot always be reliably inferred. Analogy: while type inference works well in many cases, there are situations where explicit typing is required because the type is ambiguous based on usage alone.
Oh wait, you meant Google _product_. You want Google to cater to its product needs by sacrificing own money making potential and limiting its actual users.