Merchandise and promotional items may or may not have much interest. What is being promoted is vital, but the most important factor is the condition. For these collectibles, vintage condition is paramount. If items are boxed or sealed, they should remain so. As soon as they have been handled, their value plummets. Damaged items are of negligible worth.
The value of ads and flyers for items associated with television depend on the age of the ads and flyers, what is being promoted and who is associated with the promotion. Collections of ads and flyers that center on a single program, and that create an historical document of the show are in demand. The condition of the ads and flyers is quite important, so proper steps should be taken to protect any items of this nature. The more they have deteriorated, the more their value diminishes. Autographed ads and flyers have greater interest than those that are not signed
The value of any item connected to a musician or musicians depends on who it is and what the item is. Letters, autographs, personal items, can be of interest depending on how unique the items are. Sheet music, especially if it is an original publication from the era prior to the recording revolution is highly sought. Obscure or peculiar objects, while they may generate curiosity, have limited value, unless they cross fields of interest. If this is the case, multiple collectors will be seeking to acquire the item(s).
The value of posters is an interesting phenomenon. Mass produced posters that saturated the market at any given time carry less appeal because of their abundance. However, original posters designed by artists of note are always in demand. That being said, simple prints on cheap stock that were distributed and posted to promote a musician or band, especially if they are from early in their history, have risen significantly in value. The condition of the posters is critical to maintaining their value.
Patch collecting, like pin collecting, has a large following. Despite this, the value of patches rises slowly, if at all. As with other collectibles, the popularity of the musician or group, and the significance of the event are the ultimate determinants of value. A large collection of patches devoted to a single artist will generate interest than single random patches.
Novelty items from the music and entertainment industry have mixed levels of interest. Complete lunch boxes promoting certain iconic characters are in great demand, as are vintage music memorabilia. Popularity, condition, and scarcity are important in determining value. One way to get an idea as to the desirability of a novelty is to visit auction sites looking for comparable items. Monitoring the bidding for them is a good way to tell is an object is worth collecting.