exactly. He plays for internal market. And internal audience eats him. 25 years ago, back in USSR, we laughed watching a criminal asking Arnold in Red Heat "Kakie vashi dokazatelstva?" (what are your evidences?) Western mentality is so logical, evidences-shmevidences :) Such an easy target for a showman in Russia performing for Russian audience...
"Yes, i want to be in Russia"
and
"No, i want to be in Russia"
and that point is that it doesn't matter. You come to the polls, you don't come to the polls - it wouldn't change anything, including the poll results to the 7th digit after the point :) (i'm not saying that this referendum results was cheating - it just happened that no need to cheat here, though Putin wouldn't have any issue with cheating if it was needed - again it just doesn't matter, 90% or whatever would be in any case) It just makes an overall gray routine just a little bit fun.
If you knew the history of this region (or at least last 20+ years) you'd not spent any effort typing the word "sham". Decorating the vote with all the bell and whistles that would supposedly make the vote "legitimate" (as if anything could make such a vote "legitimate" in the western eyes :) would change nothing in the vote's result, so Putin just didn't bother.
http://en.wikipedia.org/wiki/President_of_Crimea (very democratic elections result of which was nixed by Ukrainian troops an year later :)
Don't get me wrong, i don't support the annexation. My point here is that trying to play the "sham" card leads nowhere in that situation because it is immaterial.