(WARNING! The below is my opinion on how people think in terms of games, mods and tendencies on spending money)
When it comes to mods or DLC, I think people are more willing to spend money if it's optional, or as a donation, rather than "forcing" it via a price tag.
If I buy a game, and it has tons of paid DLC (Dungeon Defenders),I rarely (if ever) will pay for those, and will probably stop playing because now I feel "left out".
If a game is good enough and allows modding, people will make awesome mods (Starcraft, WarCraft3). That in turn will draw in even more people. Before you know it, you have a huge modding community, lots of awesome mods and maybe even ones that spark something new (DoTA).
Now here's an interesting hypothetical question. Do you think DoTA, LoL, DoTA2 would exist now if Blizzard charged for modded maps in Warcraft 3? We can speculate of course in either direction, but it is interesting to think about. I might be inclined to say no. Or at the very least, might not be as successful.
I just remember playing Warcraft 3 for hours on end simply because I could play this map, and then go play another map which was a completely different play style than the first one. If those maps had cost extra money, I certainly would not have spent it, and I would argue that Starcraft or WC3 might not have been as popular as it was. Maybe only as a niche eSport, but not for casual player that wants to check out all the cool and different maps people have made.
Anyway, this is just how I see it.
I think games which allow modding are more successful when the mods are free, and donations optional. Seeing a price tag on a mod (or in the proper term, DLC) is enough to drive most people away after playing through the original game.
Mods keep people around. And if they cost money, people are less likely to stick around, thus dispersing the modding community.
Last edited by Forge; 25/07/14 04:56 PM.