Negative, Mr. King.

10% baseline is safe to assume.  I believe some Japanese games like Demon Gaze & Senran Kagura were pushing more than 20%.

Ubisoft said that their titles were getting 15-20% of their sales from digital.

I don't think this could be applied to every console though.  Obviously there's a lot of benefits for going full digital on a handheld vs. a home console.

actually i remember correctly

http://www.gamesradar.com/ps-vita-game-sales-are-one-third-digital/

i usually dont say these stuff unless i remember reading them. the digital sales are different from game to game of course but still, digital sales are in no way little when it comes to the vita

it certainly doesnt apply to every console, but the thing is that digital sales are already big on consoles, Sony and nintendo already made every game released available on the online stores with Vita and WiiU and i see that trend continuing with next gen consoles, thus the cotinued rise in digital sales

That's a fair point actually.  A higher portion are going to be sold digital because the vast majority of Vita's library is digital-only; but 0 games are retail only.

All the more reason for making an effort to track digital I suppose, since this trend is only going to increase in future.

Sales will always matter.

If you hold 60% of the market, its a large incentive for any publisher to give you an exclusive or at least a timed exclusive. Look at Mass Effect, BioShock for early gen examples.

Each sales unit matter.

Sales will always matter.
The higher it is the HW penetration rate, the more profits are you bound to have and to, in the future, garantee your business. So, it will always matter to increase your sales as much as you can and the rest will follow.

Only fanboys who feels their console of choice is about to lose the current/next gen will think sales won't matter.

Sales do matter, but profits are more important.

Do you guys think digital sales will be more easily trackable next gen ? 

No, especially not by this site.