It depends on how consistent that revenue is. Have you been earning $3000/month for a few years? A few months? If a few years, then I would put a 1-2 X annual revenue, which puts it at 30K-60K. If a few months, then probably 1/2 year revenue, which puts it at 10-15K.
Also, consider the affiliate relationship. Is it easily transferable? Do you have any special relationship?
Lastly, do you spend any money on advertising, or paid links?
1-2 X annual revenue sounds pitiful, especially when we hear stories of acquisitions with 100 X multipliers. But keep in mind, you're selling a website not a startup. Buyers will always keep asking you: Why the heck do you want to sell if it's earning you that much money (EVERYONE says they want to move on to something else, so they'll be skeptical of you too)? Thus the low multiplier.
