The page rank has zero value now and it depends on the back links only. You can optimize your website yourself without contacting any company, I've seen many instructions in this forum in the other topics. Optimize your content, your title and meta description, submit to directories, buy or exchange backlinks. None of the companies can ensure you'll appear on the very top for your best keywords and taking into account that more and more companies come onlinr every other day you have to do optimization all the time, it's not enough to make it just once.