What, in your opinion, is the best investment you have made in your forum? For me, I must say that it has been to use vBulletin as my forum solution. But I haven't given it much thought and I cannot recall all of the investments I have made to-date.
A computer system and Nintendo DS for my stepson. Helps keep him occupied when he is out of school and I need to work.
This is a bit of a tough question to answer - it's difficult to choose just one item and/or "conceptual" idea. Purchasing both vBulletin and IP.Board licenses, by far, has proven to be an excellent decision. While I have nothing (personally) against the plethora of free forum scripts available for use, I'd rather go with a commercial script that has some sort of strong financial backing (i.e. thinking of the future of these scripts and their development). Sure - I could build and develop a successful community using MyBB, but I can't see myself using it, in all honesty. I also feel that it's crucial to invest in some form of dedicated hosting, such as a virtual private server or a dedicated hardware machine.
It was a great investment, within the first month I started seeing lots of stuff start showing up on the first page in Google and visits went way up. PS. Visits = $
Who knows if it's brought in members or money, but one of the best things I did to set my best-performing forum apart was commission some custom graphics and smileys. People see them and know they're unique because they wouldn't work anyplace else.
I think it's worth it if it has some feature you really want to offer your community that can't be done--or can't be done well--on free software.
I have to say I was able to run a pretty active community (10k+ members) on a phpBB install, obviously with a few SEO mods etc. The reason I upgraded to vb + vbseo is because my phpbb install was getting out of date, and I couldn't upgrade the version without losing all my mods so, I guess my greatest investment was VB, but only for security.
