[streekyd]

Syd brings up a good point for marketing.
CRL and Somaca both have private label programs for thier glass cleaners. If you have the opportunity to private label the glass cleaner you can sell/give a can to the customer as advertising. Good will goes a long way. The customer has your contact info, they have a great glass cleaner and WORD OF MOUTH comes into play.

Just a few random marketing thoughts.