There is obviously a problem with the layout of the forum's signup page, as nearly 100% of new members have to be reminded to return to the page and add their location. That would indicate a problem with the actual layout of the signup page.
I'm fairly certain that it's outside maddie's control, but I also thought it was worthwhile asking the question
Can the page layout be changed, or an alert added to make it clearer that the new member's location is important?
Just asking
