DEFINITELY NON-IMITABLE
Havix

One year, my wife and I planned a vacation to southeast Asia.  As a precaution against contracting the Hepatitis A virus, we decided to get inoculated with Havix, a product made by SmithKline Beecham.  The vaccine is said to be 3 times as effective in preventing Hepatitis A as its competition: products utilizing immune globulin. 

I contacted our physician, and was given a perscription to pick up the serum at a drug store and bring it to his office to have it administered.  At the local drug store, I asked for enough Havix to inoculatethe two of us.  The pharmacist rang up the purchase and presented me with a bill for over three hundred dollars.  I was shocked by the price...but considering the potential consequences of not being inoculated, I paid for the drug. 

Havix is an example of a product that is not imitable.  SmithKline Beecham has a patent on the vaccine and a copyright on the name "Havix".  These are isolating mechanisms sufficiently strong to prevent imitation.
 

SOMEWHAT NON-IMITABLE
Prozac

Prozac is an anti-depressant drug manufactured by Eli Lilly Company.  Since its approval by the FDA and its introduction, sales have skyrocketed.  People are taking the drug not only for depression, but also to enhance their normal personality. 

On March 20, 1996 the patent protection for the drug ended.  Immediately Novopharm Ltd., Apotex Inc., and Nu-Pharm Ltd. began shipping generic products identical to Prozac in every way but color.  Eli Lilly Company appealed to the courts for copyright protection of the distinctive shape and color of their generic Prozac.  However, in the name of patient safety, competitors claimed the right to sell their products in the same shape and color as Prozac.

The marketing of Prozac is an example of a product that is partially non-imitable. Even though Eli Lilly Company does not have patent protection, the company has been able to create isolating mechanisms of brand name, shape and color.
 

DEFINITELY IMITABLE
Aspirin

In 1897, Felix Hoffman, a German industrial chemist, synthesized acetylsalicylic acid.  His employer was Bayer and Company, and they named the new product aspirin.  Today, Americans consume about 80 billion aspirin tablets a year. 

The problem is that the majority of those 80 billion aspirin tablets are made by Bayer's competitors.  Aspirin has become so much a part of our language that Webster's dictionary does not even link the word to the Bayer Company. 

Aspirin is an example of a product that is completely imitable.  The product has no isolating mechanisms, and in fact has become synonymous with the generic product.