It actually looks fairly legit. Basically you can expect to get your email inbox BOMBARDED with advertisements. Also, free is only for the strings. They are still requiring you to pay $2.98 domestic shipping and handling, AND they don't say what type of strings they are going to provide you for free. So, it makes me wonder if they are just strings that normally cost around $5, which you could buy in bulk yourself and end up paying the same price as the shipping and handling ends up being per package of strings.
They also DO state that they will share your email with third party advertisers... so pretty much they ARE going to sell your email address. You are NOT going to just get bombarded with adverts from them, but from everyone they make money off of by handing them your email. I don't think it's worth it for $3 strings personally.
Art and beauty are in the eyes of the beholder.
What constitutes excellent music is in the ears of the listener.