I realized how many colors they come in after following one of the links in this post. They also come mixed with a variety of spirits.
QuietShootr, I can understand your reaction. The same website I went to offered the raw wormwood and such like you mentioned, and another form which I can't recall. I had never seen the extract offered separately. One product's content is enough to make a 750ml bottle of booze a bitter (tripple/highest thujon content allowed) but they hint that if you mixed with less alcohol, it would of course be stronger. Then another product they carry is enough for 35 bottles of booze. They have mix kits and even a bottle that comes with a dropper to add that "kick" to your favorite beverage. Each product came with instructions (yeah, like anyone reads those). They even have absinthe soda!
I'm quite sure that many people who buy the bottles of liquid essence get it with the intention of abuse (hmm, a little is groovy, how about a crap load?!)