Don't have an exact figure since I use the same referral tag on different sites but my estimation is about $100 per month in commissions for this one page static website. Domains are inexpensive and they are the cheapest investment you can have, so I would suggest getting it. However make sure you get the SEO right. If you Google snugies, the first result is the link to the above site. Try to have yours listed within the first 10 results for the prime keywords.

Good Luck!