5. Measure, Analyze, Optimize
Measure each and every sampling campaign to ensure it is tying back to your business objectives, and push your vendors to provide actionable data and analysis. Based on the findings from the data, continually iterate and optimize your campaigns to ensure you're maximizing the efficiency of each tactic.
Following these steps certainly requires more upfront planning, but it should yield much better results zoning in on the right customers and getting them a product that will delight them, rather than get tossed in the trash. This approach also requires constant monitoring, measuring and modification to the sampling program, but if your goals are awareness, growing the product category and increasing customer conversion, this level of diligence is well worth the effort.