Any ideas on unique users per month value?

[sincere]

I am trying to sell off a few domains, I have not promoted them really, but naturally they are gettin 15-35 uniques per month. I see this through Sedo. I have some generic terms and/or catchy names that can easily be brandable or promoted. Any idea on how to value something like that? As an example:

Click2gamble.net - Unique Visitors per month*: 23

Thanks