Interesting piece here about an experiment showing how only a minimal degree of touching a product can encourage purchase.
The article talks about a sense of ownership. I suspect that plays a role but there is also a more fundamental effect of touch / interaction with a product.
Given that a purchase decision involves a conflict between areas of the brain associated with dopamine/reward (nucleus accumbens) and that associated with fear (insula) the touching presumably tips the balance in favour of the rewards.
I saw a presentation on data visualization that spoke of how we process information and how the feeling of being able to touch it helps us process it. So presumably promotion of services needs to leverage this also.
Digital technology allows a great deal of opportunity to create the sensation of interaction without the physical product being there.