As an estimate... how much time you think you spend actively driving traffic to your site? If you handle more than one site, go with your main one that you promote more than any other.
Which is to say... building thumbnail galleries, submitting to link lists, search engine optimization efforts, promoting your affiliate program, corresponding with other webmasters about promotion/marketing in particular, following up on leads or prospects or potential traffic sources, researching where to try and get traffic from, etc.
Ballpark 8)