As other reviewers noted, these socks are a good value. They work well with the Vibram Fivefingers and appear to be pretty durable, although I just received mine. The price point is definitely a plus over the competition. BUT, I ordered the 6 pack (3 pairs black and 3 pairs navy). I received four pairs black, one pair navy, and one black and one navy sock. Perhaps I got the 3rd grader pack. Quality control should go all the way thru packaging, not just manufacturing. I am going to email the company and find out what they have to say for themselves. Other than this issue, a good product and value, that is why I only took away one star.

UPDATE

October 9, 2011

I must correct a point on my original review. It was pointed out to me by customer service that I actually ordered a pack with 4 black and 2 navy pairs. They do sell a 3 and 3 pack (and that is what I thought I ordered), but my mistake there. So, I was only out a single navy sock. Speaking of the customer service though, I received emails from them over last weekend (both Saturday and Sunday!). It is my experience that it is difficult enought to get an intelligent response from most customer service departments, much less over the weekend. As promised by the company, I just received an extra navy sock to complete my order. Everyone can make mistakes, but not everyone corrects them. Riverstone did, and I have no complaints on the product at this time.

I am not a runner. I wear my two pair of Fivefingers casually. I also do not own any Injinji brand socks. Thus, I can not compare the two sock brands. I am not sure what the durability of the Riverstone socks will be over the long term, but so far so good. I will note that I did not experience any significant shrinkage after washing as noted by another reviewer. I am a men's size 12, and the socks still reach above my ankle after washing. Seemingly a very good product at a fair price.

Now that I can change the star rating on this review, I have given the product Five stars, with the extra star for the excellent customer service. I am also going to re-post this review with the correct article I actually ordered. Their product mix seems to change quite a bit and that pack was not listed when I posted this review.