Have ever had that unpleasant feeling of having to make a present to someone, but not knowing what to buy? 99% of the times, this type of uncertainty does not help users completing their purchase. The same happens on your shop. A customer comes to purchase a present, browses the catalogue in search for an idea, but he cannot be sure about what the recipient could like most and has many doubts: how does refund policy work in case the product should not be good? And if the size were not the right one? And if it did not arrive in time?
YiThemes - YITH WooCommerce Gift Cards v1.8.0