Research: Party Favors And Options

Im doing a research project for a client who has expressed interest in getting into the party favor business. They are a large supplier of low priced products and want me to research the party favor market.

What are the hot party favors?

Is there a standard quantity of party favors? I know this is a dumb question, but they are interested in packing party favors in commonly ordered quantities to lower costs to you.

What is the standard lead time for ordering party favors, do you order per event or keep inventory on hand?

Thanks for your time