Examples of situations where the seller usually has better information than the buyer are numerous but include stockbrokers, real estate agents, and life insurance transactions.
Examples of situations where the buyer usually has better information than the seller include estate sales as specified in a last will and testament.
This situation was first described in by George Akerlof (who coined the term asymmetric information) in his 1970 work The Market for Lemons. He also noticed that, in such a market,the average value of the commodity tends to go down, even for those of perfectly good quality. It is even possible for the market to decay to the point of nonexistance.
Because of information asymetry, unscrupulous sellers can "spoof" items (like software or computer games) and defraud the buyer. As a result, many people not willing to risk getting ripped off, will avoid certain types of purchases, or will not spend as much for a given item.