I ve noticed that as well That s actually what confuses me the most If it really is a single why can t I buy it anywhere Honestly I think that if people write it as a single they don t really care if it isn t available separately simply calling something a single doesn t specify whether it s promo or not For people trying to cater to consumers like Billboard com reviews if it s a popular hit and or music video people know it it doesn t matter under what technical details it was released But I think the difference is that since we are able to specify this we probably should We should try to reflect the reality I don t think having a music video and a high placement in charts does anything to change the type of single it is I ve seen music videos for promo singles many times before even some for album tracks Isn t it a promo single nevertheless if it s only available separate from the album for promotional purposes It s not like this is degrading the single in any way either some artists just don t release subsequent album singles separately for consumers because they d rather prefer they buy the album