Gift cards are given to people as a gift or used as a promotional material by a company to promote its brand by offering discounts to people that use the card. It is loaded with money, which is the face value of what it says. It can be described as a prepaid card and most are issued by one of the major credit card companies.
These instruments when issued by a credit card company normally would contain the logo of the company on top of it and this serves as a mark of authenticity for the card. It also suggests that the card can be used anywhere that particular brand as described by the logo is accepted. For example if it's issued by visa and has a visa logo, then it can use anywhere visa is accepted.
Individuals that receive cards in place of a present, and do not care for the brand that offered the instrument could decide to spend it elsewhere. For example getting a sears card, but you do your shopping at JC Penny, and therefore will use it there. Some people feel guilty that the presenter of the present might be offended if the card is used elsewhere and most times will ignore the card until it expires wasting whatever amount of money that was loaded on it.
Are gift cards traceable? Short answer, yes, any prepaid money instrument is traceable because it has numbers and identifying features that makes it possible for you to use it for a transaction. However, that does not mean the purchaser can determine who is using it. If the gift was purchased with cash, the issuing company will have the information that card number, for example 54 was used to make purchases at this particular store, but it would not know who used it.
Furthermore, if the card was purchased with a credit card, the card company will have the info that the gift card purchased with Mr. Joe's credit card was used to buy stuff at some store.
In a nutshell, gift cards are traceable by the issuing company as to the fact that it was used; However, determining who used it exactly would require a lot of tracing and research that is not worth the trouble for an individual.