The main ingredient of any perfumes or fragrances is in its oil concentration. The higher the oil concentration, the better it is for the perfumes. The most concentrated and high quality fragrances contain 15% to 30% of perfumes oil. Commonly used fragrances are eau de toilette which contains 5% to 8% of oil. The balance of the mixtures would contain water and alcohol.
The reason why alcohol is mixed with the oil is to make the perfume smell stronger. This is especially done to some fragrance type which contains low perfumes oil. For example, eau de cologne type of perfume has 3% to 5% of oil. In order to make the perfumes smell stronger, alcohol is mixed into the ingredient.
Majority of commercially sold fragrances are mix with alcohol, which causes the scent of the perfume to evaporate faster. When you first spray a perfume with high alcohol content, it tends to smell strong initially. After an hour or two, the scent of the fragrance diminished considerably, meaning you cannot smell it as well. Alcohol-free perfumes last longer, and they go on much more subtly. They do not evaporate very fast. Some non-alcohol based perfumes can last longer up to 12 to 24 hours.
Another difference between the alcohol and non-alcohol based perfumes are in their bottling and pricing. Most non-alcohol based perfumes are packed into a small bottle since it contains pure perfume oils. For the alcohol based perfumes, the bottle come in a variety of sizes and designs. It is very obvious that the bottle design is very attractive and in terms of pricing, would cost more. If you can afford to buy pure perfume, it is much advisable since it is cost effective and its smells last longer.