I always write thank you if I win a giveaway (it would be very rude not to, in my opinion), but never just for entering a giveaway-- don't want to clutter the user's inbox.

I think the change in attitude might have happened because of the messaging system. I don't quite remember if you used to get notifications for people posting comments on your giveaways back in the day, but you get them now, and I imagine some slightly OCD people (like me) get annoyed if they have 300 notifications, so they go to check and it's all generic "thank you" spam. I know for a fact some people hate the notifications and blacklist users that cause them for no reason, so maybe there's that.

The only time I don't like it is when it's obvious someone is using a bot or script to enter and/or auto comment and you get the same comment from the same person 10 times in 10 seconds on 10 different giveaways. When that happens it's obvious the person didn't even look at what he was entering for and there's absolutely no chance they're giving a heartful thank you. They're just trying to win something, anything, spending all their points and they don't care. I'd rather not receive their spam.

I like the thanks comments as long as there's not a ton of them.
And no, I wouldn't blacklist someone for saying thanks. That's over-reacting.

I like the thankyou's it shows that the people atleast care enough to say it :P

Just ask for gifs, its better

I don't blacklist for saying thanks or not saying thanks when entering. The only (it's just common sense) thank you that matters is a winner of a giveaway of mine that says thank you for his win.

In my modest blacklist (69) there are indeed formal winners that were too rude and/or too thick and/or too entitled to say a simple thank you...

It's just basic manners 1 0 1.

Honestly? Writing thank you for every giveaway I enter would be exhausting. I tend to go without.

What I do however: I contact the person of the giveaways I win and thank them personally. No cliche "oh thank you for making a giveaway," - just expressing my heartfelt thanks for their charity. Seems more meaningful. More suitable.

Honestly that's one of the reasons I dislike the new in-build CD key transferring system - it makes it quite a bit harder to e-mail the person and thank them!

OP's case is similar to mine. I used to write "thank you" message to every giveaway I entered. I thought it was polite manners.
After 1 and 1/2 years offline, I was adjusting new Steamgifts' system. Then about 2 weeks ago, I made some public and group giveaways with leftover keys. Let me count them, 35 keys. My message window was walled with "thank you". Of course I appreciate that, people spent time and energy to type(or Ctrl-V), but it was somewhat overwhelming. I thought, "Oh my, I spammed gifters unknowingly, would they be annoyed?"
I guessed it's possible for someone to blacklist me because of it. I didn't want to annoy them.
So after that realization, instead of writing "thanks for the chance!" to every giveaway, especially when there are multiple giveaways from one person, I write something like "thanks for the many chances!" to only one, also trying to answer gifter's comment. If they don't like it, well I don't know. :(
Anyway, I only blacklist people who broke Steamgifts' rules(in case of private giveaway, my rules, haha), so I don't mind people's "thank you" message to me, only worrying if I make other gifters annoyed. Well, that's me. :)

The only thanks I want is from whoever wins the game, I don't mind the other thanks spam but it's meaningless imo.

If whoever wins can't be bothered to say thanks, then I get a little mad.

I don't like them.

So I am spending money and making giveaways for other peoples and they only say: "thanks" in every gib?
Yea - I feel their thankfulness.. :(

I guess there are something about 0,1% of people who actually write them.
Other 0,9% copy paste "thanks" into every damn ga they are entering - uh! Yuck!
And another 99% is just boots with either auto-enter , either auto thanks for every gib...

"Nothing" is better than that - for me.
I enjoy creativity and effort - even a little like "Thanks Zombie Bro!" is amazing!

"Thank you" - never..

This is... quite a grey area of debate. I mean, I used to say "thanks!" or some variation of it at first... Then started noticing more and more people who didnt want or disliked people spamming said messages on all their giveaways. And some outright blacklisting anyone who said "thanks" (this is, before winning ofc).

Nowadays I just don't post anything, unless:
1- the gifter asks for something (gif, image, text, etc);
2- the game/description has something worth of commenting on (rare game; gifter tells a short story; gifter recommends music/video/etc);
3- another comment in the GA is worth replying to;
4- I won the game and wish to thank the gifter;
5- Not entering the GA, but wish to share feedback about the game being gifted.

Outside of these exceptions, I don't really post "thanks" anymore, because far too many dislike having their inbox full of these or because they do request against it. I also dont feel like responding if the gifter didn't even take one minute when posting the GA, to say something meaningful at least, and not a cold "bundle leftover. good luck kthxbai". If someone blackslisted me because I didn't say thanks on their GA and they had no description or anything... Oh well.

Personally, I prefer GAs where the gifter says something in the description, comments or asks something even as silly as "tell me a joke!" "tell me why you want this game". Because it allows me to interact with the gifter or someone else there, and show that I do appreciate the GA even if i'm not a winner. But perhaps it's because I only enter GAs where I do want the game.. and not mass-enter every single GA until my points depleted for the day... just for bragging rights about my huge pe--i mean, collection! I suppose some also do it for the cards collecting, but eh... something tells me this isn't the most common case...

I am also frankly sick of people who post the exact "same" comment in every-single-GA, sometimes it doesnt even match whatever the gifted game is about! (hello mr "This game looks fun, thanks!" kind of comments, even if its not even a game but something like RPG maker or a DLC lol!). I mean, duuude, at least try to read wtf the GA is about before copy-pasting your bloody generic post! D:

I don't think there was ever a rule about writing thanks, you could do what you want.
The thing is, now with reply notifications you could get a lot of "thanks spam", so a lot of people don't want to deal with that.

I prefer that rather than none at all. At least there's something more to do while browsing the site.

I don't mind the occasional guy that leaves a thank you note on a great game he enjoys or will enjoy - I myself always thank the guy when I happen to win a game.
On the other hand I really dislike seeing people with 3k+ comments in 6 months leaving Thank you on my giveaways. They clearly don't mean it, which begs the question : then why do they do it ? Any answer I can come up with displeases me.

That and the fact that it pointlessly spams my inbox.

So now I just ask people not to thank me in the description, I may appear as an asshole but at least I get original comments and fewer of them !

(I shit you not, 3k comments in 6months happen more than you would think !)

I feel neutral about it. If there are much comments saying thanks it feels like spam, but if no one comments one of your GA's it's still disappointing >< (that 50/50 tho).

Winner's should write thank you. No need for several hundred generic "thanks" that lead to excessive notifications.
I see people with hundreds of active GAs all of which have hundreds of entries. If every entry said thank you, you would be left with thousands of notification at a time.

Wow I'm happy to see that at least not everyone hates the love and actually 50% voted for liking the thank yous.
But I don't necessarily agree that no "thanks" isn't bad, sometimes they really are just bots and insincere?
Besides, most of the great giveaway owners ask for something else like a gif or youtube video suggestion :D