There is some glare on the top of the balls and a shadow! Also looks a little washed out. Tweeking the contrast would have helped I think. Great idea though.
A bit too bright on the top of the golf ball. Shadow underneath the golf ball a little distracting. Suggestion would be to have this photo shot on the green (smoother surface) on a golf course. This photo/advertisement has a lot of potential!
Your balls are, err, over exposed... :-). Some sort of diffuser above this shot would have helped, some drafting film, thin paper, something to soften the direct light (Sun?)
Great concept and I really like the tag line in your title. Focus, contrast and DOF are all good. The thing I find that detracts a bit is the composition. Think about the rule of thirds and consider a different crop. Color seems just a bit flat. Perhaps shooting earlier or later in the day would have helped.
Do you really want to show a competitor's ball in the ad? This wouls also work better on manicured grass or astroturf, the lawn grass is distracting. Nice shot, try for a bit more contrast on the bal, the top edge is washed out.