Making any significant portion of the site unable to be browsed by guests is extremely stupid and illogical. Most people on any forum lurk for a period of time before signing up, so if they weren't able to browse, they'd move on to another site.

...Which would result in less hits...meaning less revenue from adds. A horrible idea.

no because it helps atrl generate revenue for ads to help pay for the server it also gets the site higher on google.

Guest should be allowed.