Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
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content containing commercial activities and/or sales without our prior written consent such as contests , sweepstakes , barter , advertising , and pyramid schemes ; 

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. OPTIONS: ['Unilateral change' 'Arbitration' 'Limitation of liability' 'None'
 'Choice of law' 'Contract by using' 'Unilateral termination'
 'Content removal' 'Jurisdiction'].