Web applications are fun to build. They are like the fancy sportscar of Web sites. Web applications allow the designer and developer to get together and solve a problem for their customers that the customers might not have even know they had. That's how the blogging tools like MovableType and Blogger came about after all. I mean, before Blogger, did you know you needed an online tool to build your Web site blog?
But most Web applications are slow and tedious. Even the fastest of them has lots of free time for your customers to go get a coffee, work on their dog training, or (worst of all) head off to a faster Web site. It's that dreaded hourglass! You click a link and the hourglass appears as the Web application consults the server and the server thinks about what it's going to send back to you.