Walmart or Itunes

With the success the Eagles, Journey, and AC-DC have had with Walmart, is it a better business decision to go with them, even if it cuts you out of the Itunes market? Revelation still hasn't hit a million copies sold and without the availability of it on Itunes, it seems to have lost some momentum now.
If you saw the Superbowel performance and jumped in your Itunes store to see what Journey had to offer, their current product wasn't there.
So my question is, with digital downloads becoming more of the market standard, do artists still got the Walmart route to get the initial sales number and have their product die a slow death later on, OR do you go through a label, get it on Itunes and maybe not get the initial sales but have the luxury of being found easily by the masses when ever you albums gets a little publicity?
I understand that Walmart has their own digital downloads store but the majority of people seem to prefer Itunes or Amazon from what I have seen.
If you saw the Superbowel performance and jumped in your Itunes store to see what Journey had to offer, their current product wasn't there.
So my question is, with digital downloads becoming more of the market standard, do artists still got the Walmart route to get the initial sales number and have their product die a slow death later on, OR do you go through a label, get it on Itunes and maybe not get the initial sales but have the luxury of being found easily by the masses when ever you albums gets a little publicity?
I understand that Walmart has their own digital downloads store but the majority of people seem to prefer Itunes or Amazon from what I have seen.