Cinco de Mayo is a real holiday, although it does not commemorate the occasion many people presume. It is not Mexican Independence Day; it commemorates Mexico’s military triumph over the French in the Battle of Puebla on May 5, 1862. Even as artificial as it may be, it creates a real opportunity. Generally speaking, these kinds of created events are done for a short-term jump and some sort of profitability, and generally speaking they get it.’’ Marketers are rarely shy about injecting commercialism into the holidays, whether it is Christmas, Mother’s Day or Valentine’s Day. But a selling season based around Cinco de Mayo? Turning Cinco de Mayo, in this country once a regional Southwestern celebration of Mexican pride, into a two-week bacchanal of beer, tequila, chips and salsa is the latest attempt by marketers to create selling opportunities where none previously existed. Long John Silver’s, the seafood restaurant chain, decided that Lent, when Roman Catholics do not eat meat on Fridays, is a perfect time to advertise its fish menu. Toys ‘‘R’’ Us heralded a two-week pre-Easter sale this year with a significant marketing campaign. In January, Office Depot ran new television and radio advertising for a back-to-business effort, just as many companies have back-to-school sales. Who cares? It is just another time to party!