I did some calculations and I definitely think this will be at 200k US sales by the end of this year. With Black Friday & Christmas push it should probably even get to 220k. It's at 140k sales atm. It also sold 290k WW so far and I predict it to be at 400k WW by December.
It either continues to sell good or it'll drop hard in 2016, it really depends. I am sure it'll get some great promo spots and tour will help it a bit as well, so it depends on how well the 3rd and 4th (maybe even 5th single) do.
We can't really say at the moment, but I am positive it will top Stars Dance's sales. 400k-500k US sales is possible and 1M WW as well.
