For someone who is looking at a specific product, holding or touching that product can create purchase intent. Another benefit is the customer's ability to recall the store itself. The more of your customer's senses you can engage the more likely he/she is to recall that moment.
This is why so many retailers are using sound and smell as part of the customer experience but it's tough to engage the sense of touch unless the staff is driving it. And since so few retailers have an engaging staff, a strategy of getting products into every customer's hand can differentiate you from your competitors.
The easiest way to engage customers with a product is when they're looking at or for something specific. Whenever you are showing a product it should either be in the customer's hand or the customer is being encouraged to do something that has them physically engaged with the product.
Let me use some non-traditional examples. If a customer is looking for a garden hose you might pick up the best hose and hand it to them so they can get the feel of the actual product while you tell them its features and benefits.
But sometimes you can't actually hand the customer a product. Say a customer is looking for a 50 lb anvil. While telling your customer the features and benefits of the anvil metal you tap it, demonstrating its solidity and strength, and ask them to do the same.
I'm not sure how many people are buying anvils ever since most cartoon characters quit dropping them on each other's heads, but I do know a customer will touch the anvil if you do it yourself and then encourage them to follow your lead.
But remember, the goal should be to engage every customer with a product, not just those looking for specific products. While you don't want customers to feel they're being accosted by employees trying to put a product in their hands, the key is to look for and create the right opportunities to do so.
When a customer asks about your company, take a moment to put a product in his/her hand while you answer the question. When someone is at the register you can place one of the impulse items in his/her hand before starting to ring the sale. And sometimes you might want to show off a new product that just came in.
Many years ago my friend Josh was determined to sell the most tennis racquets at The Sharper Image so he could win a trip to the U.S. Open. He carried that tennis racquet around every minute of the contest. More important, he put that racquet in the hand of just about every customer he talked with. Even though only a few customers actually bought a racquet, almost all of them were fine with him handing them the racquet because he was so enthusiastic about it. Of course you can guess who went to the U.S. Open that year.
Every day you work the floor, remember that a product in the customer's hand is worth two on the shelf. And if you accomplish this regularly, in your store the expression will soon be "one in the customer's hand on none on the shelf."