Increase PR/traffic

Require increase of PR and traffic to one of my sites. Only legally allowed techniques to be used. All bidders need to advise how/what they will do to achieve traffic and increased PR. This is most important. I will prefer bidders who work on a monthly fee. I prefer this because I know that I can discontinue if I feed that the desired results are not being achieved. (Do not ask for initial lumpsome amount). The current PR of the site is PR4 and receives over 200 unique visitors a day. It is a B2B site. I will give name of the site only to those bidders whose quotation is workable and if they follow legal promotional techniques. Note : First month's payment will be sent through getafreelancer escrow system and released once we see that you have done some promotional work. Future payments can be done through Paypal. Any changes that you suggest need to be made to the site will be done at our end only - few changes possible.