Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
( e ) our `` forever '' subscription is paid for by a one-off upfront payment . 

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