Looking for someone to market and run social media for a new retail company

I am looking for a PR person or company who can help with marketing and socail meidia for a new online retail company. It will require about half an hour a day so a total of three hours a week posting links and updating facebook and twitter with links and images as well as pushing for ticket sales for the launch event of the company.

I will need to speak over the phone to give a bit more detail.
Its not a great deal of work but needs dedication and consistancy.

Could lead to a permament contract