Infection is also a cause for concern, as feet are the hardest place on the body to keep clean so recovery time is going to be a lot longer compared to an arm tattoo. This may not be a problem if you live in a nice warm place as you can go bare foot for a while but if you live in Alaska for instance this may be a problem. Upon leaving the parlour with your cool new tattoo the last thing that you are going to want to do is squeeze you foot into your boot. After-care is an issue too.
Putting your feet in and out of shoes all day takes it's toll on the tattoo and it will probably need touching up a lot quicker than a tattoo anywhere else on your body. This is because of ink blurring on the edges due to the pure punishment that your feet take in everyday life. They can look stunningly beautiful done right but the truth is that they don't look good for very long.