JK,
>For sure, but your requirements analysis should expose this need before a single line of code is written.
>
>In other cases, it's sometimes less expensive and more timely for a client to have the traditional 1-tier app written and in place for a while before considering a scalable system.
Yes, but if the possibility of web is there for some future point in time, it may make sense to have at least a logical n-Tier approach to avoid a complete rewrite. Much can be said also for building apps that way to anticipate the future needs the client doesn't realize yet.
Logical n-Tier, deployed on one physical tier, leaves you much better positioned for flexibility.