Unregistered Forum readers cannot see attachments - that likely accounts for a large part of the discrepancy
Why, and again only a query, are unregistered site visitors not allowed to look at the images posted by forum members?
I assume that was originally an historical decision dating back to the days when bandwidth considerations etc were an issue, but as that is probably no longer the case, then if they could see the images we are posting, but still without being able to contribute anonymously themselves, then perhaps they might be more inclined to join the site and contribute their images and help to swell site visitor numbers and potential customers.
Dave