Tiago, above, states that Vitacost have lost their BBB rating when in fact they have an A+ rating.
I live outside of the USA so do not find Vitacost as cheap as other companies when it comes to shipping. They state this is because the company i use is more expensive to cover their cheap shipping: this is a blatantly not true as Vitacost are cheaper on some but more expensive on other items.
So far i have used Vitacost twice without issue but i would not use them exclusively as it pays to shop around and it takes a huge saving to justify the more than double shipping costs. Remember despite what these internet companies state, you do have protection with your credit card: open a dispute with your cc company.
Use them with confidence, however, if you have a bad experience vote with your feet and go elsewhere