Tundra has several forums and they're all huge. Tundra has a ton more sales and a lot more years under it's belt. Titan also has a few large forums but its also been around a whole lot longer, same with the Armada but that forum is smaller.
The Tundra forums all had unique feels and unfortunately cliques. If you were new and asked a simple question you would get blasted for not searching. Way more participation on those forums, again due to much larger user base. In one day your topic would be a few pages back on the "New Topic" search page. It was hard to keep up at times.
Even with niche vehicles there were other forums with a lot more participation. Example would be the Toyota MR2 Spyder. I owned and raced one 3 years and was the racing forum mod on a Spyder site. That car has low sales but the forum was quite active. I think the big difference is people loved to mod their cars. From looks to audio to performance almost every single user was doing something to their car.
The Nissan NV on the other hand - you have the mods for commercial use, the mods for camping or trekking and then NVP mods. Most of the NVP drivers I would venture buy their van and just drive it. They may add running boards or tint the windows but they just own and drive. They dont have a need for a forum unless they have a problem or specific question. Even with towing, you can get a much bigger response on places like RV.net or the campers company site (like Forestriverforums.com), those forums are huge. If you had specific towing questions they could be answered here but basic ones are just as quickly answered if not quicker on other sites.
What I have noticed is there are a lot of photos in the gallery with no threads. One guy on here has The Beast, a modded NVP with custom rack, ladder, LED lights, bull bar, etc. Another a Quigly with bigger wheels, tires, a 4" lift, Aluminess rack, etc. One has a crazy custom interior done with LED lights, multiple monitors, etc. BUT, you search their username for a thread about their vans and 9 out 10 times there is nothing. Why?? I'd love to read about their vans and have been PM'ing a few of them to get info. Put it out there for all to see besides a photo.
2015 NVP SL - Silver, 20% tint, Bully Dog GT, AEM filter w/ snorkel mod, Topper Rack, Luverne Grip Step running boards, Goodyear SilentArmor Pro Grades. DRL delete, LED's
2015 XLR Hyperlite 27HFS Toy Hauler
Blue Ox Sway Pro with Tekonsha P3 controller
Me, wife, 3 kids and 2 big dogs!