When I first joined this site, I was updating the pages from the archives once a day and then when I ran out, I started posting only once a week on Tuesdays. After about a month of updating once a week, I decided that I wanted to expand my update schedule to twice per week, Tuesdays and Fridays.
To be frank, I believe that the more often you update, the more eyes are going to see your comic, that's just a fact. When I started updating twice a week instead of just once, I was getting a lot more views and reader interaction I found. If you can't handle a frequent update schedule however, there's no use forcing it. At the end of the day, consistency is king, and your readers will appreciate your consistency in the end.