Good Product. Sound Plans. No Sure Thing.
Difficulty of getting innovative new products to market discussed through experience of Doumar Products Inc, which makes un-du, adhesive neutralizer that removes stickers; buyers who managed to find Doumar's booth amid 2,000 at International Housewares Show voice delight with product that company has been trying to market for two years; photos; chronology; Prof Paul Reynolds, who studies entrepreneurs, estimates that of 600,000 to 700,000 businesses started each year less than twenty percent have new product or something distinctive (M)