Print-on-demand suppliers compared: Lulu, CreateSpace, Zenith

I've just written my promised article comparing and contrasting print-on-demand suppliers (pdf). I included the local printer I used, Zenith, for a third point of comparison with Lulu and CreateSpace. Quick summary:

• CreateSpace is overall the best for my purposes: simple but functional website, free access to Amazon, price per unit comparable to Lulu. However, the only printing fault I had was from them, and their customer service isn't as good as the other two, mainly because it's so indirect.
• Zenith gave excellent customer service and were cost-effective for bulk orders for me, because they're local. Their website needs serious work, though.
• Lulu, for my purposes, weren't worthwhile because the high cost of shipping to New Zealand negated the advantage of their excellent bulk discounts. If they print locally to you, though, it would be worth using them as well as CreateSpace.