Must I do, because I can?

Many of you may know this situation. Fighting small birds with big cannons. I started to develop an URL shortener in Java to test some Java MongoDB interaction. While working on the entities I encountered the question „shall I make it a user centric application or just an URL shortener?“.

Beside the fact, that this question contains a lot of work to be done (or not to be done), it contains a highly philosophical manner.

Should I always go the „make it work“ way, mostly because the customer pays it, or may I think it over and should I go for the longer but more extensible or feature-rich version? What can I present to my project manager without getting ripped my head off? (ok,ok the last one was moreover less a bad joke.)

I want to hear your version of the story. How much do you take extensibility into account when you look at the architecture of a project? Just make it work or do you look what might come afterwards? Feel free to drop a comment.