HELP- What makes a novel successful?

1 - selling lots of copies. Seriously, what do you think? Success is measurable, so what should there be a lot of or a little of?
2 - again, what do you think? Consider novels that have provoked thought in you. What do they have in common? What's different about them?
3 - www.dictionary.com -- check this for word definitions.

Many poorly written novels are very successful.

(This may stretch the page, so I apologize ahead of time)
You want a successful novel? Don't write like this:



Or this:

And once again, the images may not work (or just not work for me), so here is the link to see this for yourself. Click on either of the first two "essays".

http://www.angelfire.com/theforce/blix797/Essay/essay.html

We all know from books we hated what fails to allow a novel to succeed. I think success is a bit more difficult to define.