[uptown]

The difference between the two is that work for a client can typically only be sold once. Work like creating an icon set or writing a book can be sold infinitely and require virtually no post-support. Additionally, those streams of income can continue while you're working on more client work if that's your thing.

[leftnode]

Not necessarily, for some client work I've reduced my price in exchange for full ownership (or rather, co-ownership) of the product I've developed. That way I can do with it what I want.

[sidmitra]

Except you can also scale your consulting business by hiring or tying up with other devs. This means you can still earn while others are working for you!

[yeahsure]

I recommend you to read this article: http://blog.asmartbear.com/consulting-company-accounting.htm...

While I don't agree with everything he says, there's a large amount of truth in that post.