Subtle, discrete, and classy. Contrary to the flamboyant, tattoos that fit the shock value stereotype, the ear tattoo is a rather unique tattoo location.
Compared to other more subtle tattoo locations such as the ankle or small of the back, the ear tattoo is more often exposed, and has a rare combination of exposure and discretion.
I can't testify as to how painful this procedure might be, or how difficult a "canvas" this would be for the tattoo artist, but either way, it is quite easy to see how this could become a trend.
Check out some more unique tattoos:
More Stats +/-
Virtual Product Photoshoots
Protein Bar Mixes
Trustworthy Inheritance Apps
Surgical Augmented Reality Systems