how many people out of 100 see your front page? is it 10, 1, 50, 0.
Interesting point. Still I don't think I'd buy from a site without glancing at the front page. Other shoppers, I don't know.
What to put on the front page? As always, I mainly take clues from the big commerce sites. They have the volume and ability to test this. A few hot high margin products, specials, new stuff (to test how well it sells) etc.
In our B/M stores thats how we've always decided what went in our windows and ads and "end caps."