Theres several factors that can determine this.
First of all is price. Games on demand on Xbox live tend to be more expensive than at selected retailers, thus from that point of view they are nowhere near.
When you get to lower prices though, in particular with indie/small games the sales rise.
My conclusion is digital sales will never overtake physical sales until they are substancially cheaper to cover the cost of resale. And to be honest, they should be cheaper because you dont get distribution costs when you're delivering a download (or at least not as substancial). Right now, Xbox live in particular is trying to rape peoples wallet. While that persists digital will not prevail.







