Picture? I did not know such a thing exists, but at any rate it would have to be a fixed forward stab, not a real canard. If it does exist they would have to trim it for cruise and the only advantage would be unloading the tail stab to reduce the downward force. This would be optimized at forward CG, and if this airplane is used commercially in a cruise mode a lot and is loaded forward CG all the time, then it might produce a small advantage in efficiency. Slightly higher cruise speed, less drag, better range, etc. not a lot. You can get the same deltas comparing performance of a fwd CG loading to an aft loading in an unaltered model. There is also a small drag penalty for additional wetted area with the fwd stab, and some extra weight. That plus cost, and the structural issues are why these are not common. Also degrades stall-spin recovery a bit.