Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: 3 axis vs. 2 axis.  Which is better?  What purpose for each?  Thanks!Hint: I mostly do beach/landscape photos.
Document: Finally, I have the help that I need to take better pictures. It fits perfectly in my camera's hot shoe. This is my first level so I have nothing to compare it to. But with three points of reference, it more than met my expectations. My photos are looking much straighter now. Thanks!
When not using my tripod, it's also nice to know if my shot will be level. The level is great when taking landscape shots because I cannot always rely on the horizon line for level. Plus, it's a great addition when taking night shots. If you're like me and don't want to always have to adjust level in post-editing, it's worth the $7 to buy this 3-axis level. Not only is it worth the price, but it comes with a microfiber lens cleaning cloth.
On the 3-axis cube, only 1 bubble at a time is useful.
I have a Canon T1i and a tripod that has a level, but I found it to be a pain to always be adjusting the tripod legs to fine tune the level. Also, the tripod only has 1 axis. So, I decided to try out this 3-axis hot shoe bubble level. I bought it from GOJA and have been very happy with it so far.
I validated the level to be sufficiently accurate. This can easily be checked by placing the level on any surface and rotating the level 180 degrees to see if the level reads the same as before. Repeat three times for each axis. None of the claims of it being not true explain how they know it to be not true.3. You need a tripod for it's use. I bought this explicitly for hand held panoramic photographs.
It was a tight fit for my D5200, but I want it tight so it doesn't get lost in the field. I'm using this to level my camera for panorama photos and it seem accurate enough for that purpose. I have other devices upon which I mount this cube where the fit is loose. These fitting locations vary a bit from device to device; not a real problem. I can squeeze the loose brackets and sand the cube's mounting edge w/6000 grit paper to make everything fit.
Fits my T3i hot shoe perfectly and has helped me fix my horizons in camera. I have a visual impairment that makes them tougher than usual, so I can now spend more time shooting photos rather than 'fixing' photos.
This bubble level would only go 3/4 into my camera's Hot Shoe - therefore not fitting in properly or giving a true reading. I have a Nikon D5100.
I bought this level so I could take hand held panoramic photographs. This hot shoe level performs as expected at this task.I would like to address some of the criticism against this item in the other customer reviews.1. The hot shoe fits too tightly. I have not found this to be a problem. But if it was, this could easily be remedied with a sheet of sandpaper. Considering the cost of this item, a little DIY should not be unexpected.2.
I find this product extremely useful when the camera is on a tripod. I prefer to  level the photo in-camera than try to fix it in an editor. I was wondering why the level has a third axis but realized it let's me set the camera perfectly parallel to the picture frame(duh! moment for me).The plastic hot-shoe mount may eventually break or wear off, but I'd rather have this part go than my camera's bracket.
Answer: The third axis allows you to level the camera on vertical shots. If you only shoot horizontal the two axis is sufficient.