Somewhat off topic but out of curiosity, for what genuine technical reasons would one show "There is a queue" message on the signup page? One would be very larg

Somewhat off topic but out of curiosity, for what genuine technical reasons would one show "There is a queue" message on the signup page? One would be very large no. of signups immediately following the launch. Anything else? I don't subscribe to the idea of landing pages for non existent products but I feel that if lot of new products start showing such a message when there aren't many technical reasons to do so, no one is going to believe about the queue thing anyway. OTOH, people might start using it as a filter instead!