From the license itself, it seems like you do need to include the license contents within the derivative work somewhere. Since "Derivative works" includes "Object" (compiled) projects, and 4a states:
> You must give any other recipients of the Work or Derivative Works a copy of this License
They're pretty clear on attribution being in the source only in 4c:
> You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works
According to the letter of the law probably. But I would suggest that it might be nice to credit the main Open Source project(s) on which your business is built, maybe in a 'Thanks to...' page.
> You must give any other recipients of the Work or Derivative Works a copy of this License
They're pretty clear on attribution being in the source only in 4c:
> You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works