I don't know about Brazil or Poland, but I can tell you how it was in Bosnia and Herzegovina, where I am from.
Watching Tibia leave its footprint here was interesting for me, as I grew up with the game.
Tibia oddly grew somewhat popular, but only in a few specific cities.
At the rise of gaming, many internet clubs (PC bangs) here hosted Tibia alongside some other games, and PC bangs were very popular back in the day. It was (still relatively is) a poor country, and not many children had access to good internet, or an actual PC for that matter.
Even if you had a PC, it was some bottom of the barrel office PC that your parents owned and probably used for work, just enough to run MS Word.
So, they all went to PC bangs and saw other people playing and wanted to join in. In some parts of the country, it spread like wildfire.
Internet bandwidth was very limited back in the day, unless you were paying for top tier packages offered by ISPs which were not affordable for regular folk, and Tibia had that nice combination of both being lightweight, consuming low bandwidth and being an MMO, which was a relatively new genre at the time. But the most important part I'd say, was definitely the part about it being playable despite shitty hardware and shitty internet - and the fact that most of your friends probably played it - helped the word spread even faster.
A few years later, some other MMOs started popping up in the PC bangs and Tibia's quick rise in popularity started to fade. World of Warcraft, Anarchy Online, Cabal Online, TERA, etc. However, many people who still didn't have hardware good enough to run those games, resorted back to playing Tibia from their own home.
Berylia, Guardia, Valoria, and several other servers were full of Bosnians.
It was a thing of zeitgeist, you had to be there in those circumstances in the right time.
I very much doubt that Tibia gets a lot of attention these days. If I were out there today, looking for an MMO to play, you'd have much to do to convince me to give Tibia even a shot.