If the stores have display televisions calibrate them for no charge in return for placing your business cards there and placing THX stickers on the TVs. will also get some more calibrations under you belt and expose you to a variety of new model televisions.
Go to your local distributors (AVAD, Volutone, ADI etc.) and pin up an ad in their will call area offering $100 for every customer referral. Their customers are the ones installing the televisions so they have the leads.
You have no chance of competeing with geek squad for the average joe, their advertising budget will crowd you out every time.
focus on the quality high end customers.
Good Luck!