Olive oil is a staple product in virtually every home. It has numerous culinary uses, and is even great for your beauty regimen (we talk about some of its uses in another one of our blogs Here.)
The problem is most brands are not the genuine thing. The oil is either cut with less expensive refined oils such as canola, or lesser grade olive oils to reduce the cost of production, therefore skyrocketing the profit margin. When the product is bottled, it is very difficult to tell if it is real or fake by taste or texture. In 2010, researchers at UC Davis tested 124 samples of oil from major brands, and found that over 70% were adulterated! Click Here To See Their Report.
All in all, the general consensus on this subject is that your best bet is to buy local (or as close to local as you can, depending on where you live.) It may be a little pricier, but you know you will be getting exactly what you pay for, and not lining the pockets of those who find it appropriate to trick the consumer for a higher profit.