I wonder if businesses actually sell more if their products are priced like $9.95 or $9.99 instead of $10, or that it's just based on the expectation that such

I wonder if businesses actually sell more if their products are priced like $9.95 or $9.99 instead of $10, or that it's just based on the expectation that such prices are more attractive to the customer. Unfortunately, the Wikipedia article [http://en.wikipedia.org/wiki/Psychological_pricing http://en.wikipedia.org/wiki/Psychological_pricing] doesn't mention whether any research was done to verify this, much less any results.