Sio,

With the number of users your a planing to support, I would say yes, EJB 
is important.  Futhermore, from a architectual perspective what type of 
application will you be designing?  Will there be a database? If so, how 
will you manage the connections?  A two tier architecture will not scale 
to 200,000 users even on Oracle without a big, very big, box. Most likely 
you need to use thread pooling.  With the number of users, I would say 
Yes.  EJBs will allow you to separate the business logic from the front 
end or the database and use a good number of features such as EJB entity 
beans and a concept of state and statefull beans.  

Good luck.

Kevin

> Hi,
> 
>     I've just started learning EJB and I'm wondering if using EJB is 
really
> essential in internet applications. How does the performance of an 
internet
> app/website get affected with and without using EJB? If a website uses
> Servlet, JSP, and have it's own transaction management but does not 
utilise
> EJB, is it still J2EE compliant?
> 
>     Appreciate if anyone would help clear these doubts.
> 
> 
> 
> Regards,
> Sio Poh
> 
> 
>