1. How to REALLY get sales leads.
More or less in order here are the ways that advertising sources generate sales leads (from least to best): billboards, newspapers, radio, standard TV, magazines, co-op direct mail, self-standing direct mail, card decks, direct response TV and the Yellow Pages. The hidden gems for lead generation here are the card decks (packs of postcard-sized business return cards). Card decks are generally inexpensive and usually yield very good responses. They are mainly used for business-to-business, but there are household versions, too. Note: the quality of these leads is often lower than some other media, but that can be addressed in various ways (better offer, stronger follow up etc.).
2. Give of yourself.
The cheapest thing you can do in marketing promotion is to give your product away. When you give it away (in quantities that prime the pump, not that steal your own market away), you are giving away something of significantly greater perceived value than your cost. You are also generally giving it only to a prospective buyer anyway. And by doing so, you are wedging your way into that buyer's realm of consciousness for a given product category---and you don't have a prayer until that happens.
3. A buyer's repertoire.
A given person has about 5-6 brands of products per category from which they will purchase. Think about it yourself. Don't you buy from a limited number of brands for toothpaste, motor oil, beer, jeans, soup? If you are the brand manager of a less-than-top brand, you need creativity or a much bigger budget. It's easy to BE a big brand, but hard to get there. That's when product sampling (a variation of #2 above) is a good initial step.
4. Negative event promotion.
A sly sports promoter had a great idea. He advertised tickets for a hockey game with the stipulation that the President of the United States (who happened to be coming to that general area that day) had been invited for free, and if he showed up everybody else in the crowd would get a free refund, too. Big crowd. And no, he wasn't there.