I do it every now and then fellow GAFfer.
Usually when I purchase a game or I finish one I write them a humble e-mail thanking their team for the effort and for making a good game. When I write something is it via e-mail or a letter (physical form). I almost always get an answer and I'm very happy to not only get an answer but also to get a nice answer. It must feel great for them to know how happy their consumers are and also, it feels great, as a consumer when you are heard and they thank you for the time and patience invested while writing something.
From, Guerrilla, Dice, Remedy, Respawn and many more "big companies" I got answers. I sent them some letters with the good old stamp and envelope and their replied via e-mail. When it comes to indie developers they are faster to answer and sometimes is it via Twitter or e-mail too. I'm actually surprised that, not only many of them replied but also, they spent their time doing so.
Oh and not only developers! There are great people who work in the community manager area who do an incredible job with their consumers! From Santa Monica studios to Turn10 studios I've met, talked and sent my letters and they were simply incredible. Amazing people, kind and most important, they always were ready for any question showing support and passion for what they love to do.
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I only had one case where not only I never got an answer but they did some sort of damage control:
Insomniac. A company who made so many great, amazing titles. I once wrote a letter to them. The biggest one I ever wrote explaining how happy I was for their games, how important they were for my loved one, who, in the past had cancer (Leukemia, but thank God survived!) and while she had cancer, gaming was there to pass the time after those painful sessions. It was not an e-mail but an actual letter with extra packaging. I paid extra for a tracking postage, paid extra for a bigger package since I wanted to make sure it would arrive well at the destination. Back in the day I got the info that they did receive the package. While I did not expect any answer I always wondered if they even read all of that. I would be okay to not expect a answer, it's more than okay.
Later on, when FUSE was about to get released, some threads start to surface here, in this fine community. "FUSE Unboxing", others about the Story and so on. Many of there were locked due the negativism from many people. I shared this story to some good fellow GAFfers in those threads and after reading this they were a bit surprised for me never getting a reply after such touching letter and effort (both time and money). It didn't take long for two known members from Insomniac who also post here to show interest about my "issue" (it was okay, nothing serious so I wouldn't call a issue). They said they were sorry, they usually answer or at least check their e-mail from fans and if I took so much effort of time and money as well a lot of heart, the least they could do was to check in their offices where that package was. I explained all the details. I got several PM's from GAFfers asking about what I wrote just for curiosity sake. I answered them all. Days passed and I got some PM's from them (the people who work at Insomniac) they asked for some time since they were busy. I said sure, it's more than okay. More days passed and never got an answer. Went to ask them about this on Twitter and they replied that they were very busy since it was the release week of FUSE. After the game was released I asked back and they never replied... It was just a little public damage control in here and they left me wishing they could take some effort but either way it was nothing serious and I don't regret my money and time wasted. I just don't see the point of pretending to care only to never answer back.