I love the idea. I think you could have benefitted from a fill flash or something to illuminate the bottle a little bit more. But you really can't nitpick with a background like that.
Composition: 3, I would like this shot a lot more if the bottle was placed closer to the edge of the shot. I think the off balance feel would really help
Technical: 6
Appeal: 5
Challenge: 8
Overall Calculated Average Score: 6
ok, i am voting this challenge in 2 passes. in this pass, you will get a partial comment and a score. then i will come back to comment again. if you have any problem whatsoever with this comment, pm me and let me know. otherwise, take it with a grain of salt...i'm not trying to be a know-it-all, i'm just explaining where i'm coming from in voting this challenge. and, if this comment is NOT helpful (of if you think i'm full of $#!+), don't mark it helpful.
billboards are a science unto themselves. a lot of research has gone into determining just how much information a person can digest and retain in specific time spans. they use this information to develop formulas for determining the number of words and letters to use on billboards, as well as their sizes. they also determine the size and number of visual elements to include.
the graphics/photograph on a billboard are designed to get the point across in a moment. on the road, a driver will have less time with a billboard than a voter will give your image. this is a key element in the challenge: composing a shot that will get its point across quickly and succintly. along those lines, a strong composition will probably have few details and make strong use of negative space.
They must not sell it in Thailand or Sri Lanka. ;-) Some front lighting on the bottle and move it to the far left of the composition would make it better I think. Nice job though.