believe it or not. i clicked on the freelancerstore banner at the top and hired someone from there. i did look at his portfolio and he was from india. he has done a great job for me so far. i'm currently on the first page for a few of my keyterms. Since i outsourced him out, i found a better deal than i would from the states.
certainly ask for a portfolio of their work. Check out some sites they have worked and how it works. Look at their website and see how it is optimized. Make an offer where you pay one third of the advance money and the remaining 2 / 3 of the post, it is done and keeps a watchful eye on how they do it.