Scalability of Rest-based web services

Are REST-based web-services more scalable then the situation o开发者_如何学运维f having the web-service logic embedded in a web site in terms of models and controllers (or similar)? If so, why? I have read the wikipedia article that mentions functional programming (no state), load-balancing, and cachability as reasons, but they seem to all apply to web sites (eg load-balancing). Usually the only state is whether the user is logged in or not, so isn't hard to get around.

From the perspective of REST there is really no difference between building web sites and building web Apis. The constraints apply equally to both scenarios. Therefore the scalability issues are the same.