Not the sturdiest material, but due to its design it shouldn't be supporting any weight.  If you take it off the wall and move it though, be careful to support it because our movers cracked ours in half during transit.  It is really sleek looking on the wall, we used it for more decorative pieces rather than function, but it could also be used to stack books or something similar.  Would (and will) probably purchase this piece again.