Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
• advertise or solicit others to purchase any product or service within the vimeo site ( unless you are an official vimeo partner or advertiser and have a written agreement with vimeo ) . 

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