Free Advertising is great & ideally the best way to go.    Just like professional people,  those that are really good get known by word of mouth & don't have to pay with sleasy paper adds or telephone book adds.    Keep it simple -- "ANYONE INTERESTED in $15/barrel oil equivalent energy?"    That's the theme -  cheap, non - corrosive, non-hazardous, environmentally friendly, non-flammable, non-polluting alternative energy!