Being one of the few latino anime journalists
in this little game, I've noticed in the years since the introduction of anime on DVD that many licensors and distributors would include Spanish dubs/subs on many titles, with the two biggest properties in terms of recognition in the US being Neon Genesis Evangelion and Dragon Ball Z.
When Evangelion came out on DVD in the early part of the decade, I was shocked that it included a Spanish dub and immediately set out to buy all of the volumes in order to experience the show in one of my native languages. It ended up being immensely enjoyable because the acting was equal, if not superior in some parts to the Japanese acting. After going back and watching the show in English and Japanese, I felt that the Spanish dub could stand up next to the Japanese dub equally while the English dub left a lot to be desired.
After that initial experience, I started seeking out more releases with Spanish dubs and found solace with ADV's early DVD releases, as many of them in Plastic Little, Those Who Hunt Elves, Bubblegum Crisis Tokyo 2040, Blue Seed and the Robotech Remastered/Protoculture Collection all featured Spanish dubs along with a few other titles. I was a happy anime fan in those days knowing that companies were willing to invest in the addition.
I found other titles with Spanish dubs in Irresponsible Captain Tylor, Fighting Spirit and Agent Aika, but by then, the market had begun its collapse and when ADV first announced their first of many Eva rereleases in the Platinum Collection, I was saddened to see that they did not include the Spanish dub in the new releases. Even Funimation saw the trend and decided not to include Spanish dubs on the "widescreen" box sets or the Dragon Box collections, despite it being one of the most popular shows in Latin America.
Getting back to Fighting Spirit, it turns out that Geneon actually invested the money to record a Spanish dub on their release, hoping that the Hispanic/Latino market would pick up the show based on its boxing premise, being a popular sport in Mexico and Puerto Rico. Turns out it didn't work as well as they thought it would and the show lost a lot of money for them, although it getting a TV broadcast on a Spanish network would have helped immensely.
As an example, in 1997 when Dragon Ball Z was broadcast on Telemundo, it pulled in the highest ratings ever for its block of children's programming, which was also due to English speaking fans wanting to watch the arcs that Cartoon Network and Funimation wouldn't get around to until 2000-2003. I'll close this out since I'm getting nostalgic but I hope to see the resurgence of the Spanish dub in R1 someday, although with improved and tailored marketing for the audience.
The audience is out there for Spanish dubs to be more than viable, you just have to let them know the option is available.