Définition:
The back end is a way for the author of the source material, or anybody else participating who may be eligible, to get some "profit participation." This means that they are then paid some of the profit the film makes after it breaks even. This can be anywhere from a couple to more than ten percent of the total gross after the film covers production and promotional costs, which is called the net gross. This total is just checked after the majority of the box office money has come in and then all of the other costs are subtracted from it. Now we take the specified percentage points, sometimes called net points, and take that out of the remaining monetary sum.


Back-end
Les recettes d'un film produites par l'exploitation du film sur une partie ou la totalité des marchés. Les participations à ces recettes sont négociables mais ne sont généralement pas versées avant le recouvrement des coûts de distribution et/ou de production.
http://www.obs.coe.int/oea_publ/sequentia5.pdf.fr