Does Cortana learn by Bing?

[Andd]

I was wondering if Cortana learn more about me if I do search by Bing(I guess Google Now do this with google, but I am not sure).
I am asking this because for now I'm using google, but if using Bing helped in this I would try using it

 

[realwarder]

Cortana is intertwined with Bing

Making Search More Personal - Search Blog

I switched from Google to Bing a few months ago. Bing is actually pretty good these days unlike only a year ago.