I know there are ALOT of zippos out there for sale on e-bay, and i've only been let down once, from one seller claiming to be selling an "authentic made by zippo Superman zippo) This turned out to be a zippo lighter with a superman graphic clumsily glued to the front of it. I was not happy with it. I have also been on the verge of purchasing or bidding on more than one occasion on what someone is calling an "authentic zippo lighter". As a collector, I might know more, but its easy to tell if you are selling a zippo or not (just look at the bottom!) so there is no reason why anyone should be trying to pass off another type of lighter for a zippo. Here are some easy ways to tell what your looking at when you look at lighter you think is a zippo.
1. look at how they've worded what they are selling. This seems obvious, but the difference in wording between a "true authentic STYLED zippo" and a "true authentic zippo" could mean a world of difference.
2. Look at how the lighter is boxed. If there is no box at all, but they are selling a BRAND NEW lighter, they should have a case. Almost all Zippo lighters come with their own small case. Some are plastic and some are metal, and they all say zippo on them.
3. Orange Sticker! The orange sticker is a big thing with collectors. Each zippo, when purchased will have an orange safety sticker on the back of it which prevents the lighter from being opened. Most zippo enthusiasts look for this, and most people who sell zippos often make sure to include of a picture of the intact safety seal.
4. If you see a zippo that you've never seen before, and think it might be homemade (a zippo, but with markings put on it by someone else) take a closer look. Ask the seller to send you the number on the bottom of the lighter. the stamping on the bottom of a zippo is a wealth of information. If you e-mail the information to zippo, they can be extremely helpful.
Zippos are a great collectors item, and i hope that this has been helpful.