What constitutes suspicious user behaviour for you?

Maybe he's not home? I only just found out you can activate keys on the browser: https://store.steampowered.com/account/registerkey

U can disable sg mails.
Also some ppl can't activate their wins via mobile, cause they can't login to steam (didn't remember password and login, or have steam app on PC, not on phone (for example with bluestacks)

Many people log into SG on mobile or from work or other places and can't activate a win until later when they can get on Steam.
Just be patient until the 7 days pass (and report those unactivated wins in case he hasn't been suspended).

I have seen it many times, mostly in my public GAs. Sometimes I waited for the whole week before the game was marked received and any attempt to contact the winner was unanswered.
And yes, I also agree that it seems "automated".

I wouldn't jump to any conclusions about this. I don't check my e-mail much, certainly not every day, unless I'm expecting something, and I use Steam offline sometimes, too, or don't use Steam for days at a time... Nothing particularly suspicious about this to me, just someone who hasn't had the possibility (as in not being at home as other people have said) or the time to activate, or is being a bit lazy or procrastinating, etc.

Have you not received the key within the deadline by sg rules? Or are you within the deadline yet?

Im anxious. Not so much 21 century social media crazy 'became anxious' i was born unhealthy so - so yeah, i also suffer when i win but even more so with winner taking their time to activate.
BUT... i don't complain.

There can be a number of reasons for that. I usually send as soon as i can or get online because i dislike waiting but once some years ago i took my time- reason being i made a number of gas in batch forgetting to make then end together, keys were all over the place and it was a rushed week with a bunch of college essays - so it was only when i came and all of then ended that i took the minutes to figure out where were wich key from wich bundle and sent.
At the time i didn't usually used mobile much but i did- but mobile or not between e-mails, googling and working on the computer i did entered some gas soon to end- much quicker to do then sending keys.
Also at the time i had the habit of having steamgifts as a fixed tab on chrome - to this day i don't know if doing so makes me be online everytime i opened the browser. I still do that every now and then when i find a ga i don't want to miss and im out of points- fixed tab... heck, i even fix discussions im interested every now and then.

About e-mails... rarely i was reminded by mail. This day and age i rarely check e-mails and rarely receive important ones- most ugent things are sent to me by other means.

I did that once and avoid it but... my point is:
Where exactly is the problem or the wrongdoing?
What could the user be doing of so sketchy and suspisiouss 'holding on' 'your' key, the one he is gifting you?

And if someone seens automated... maybe they are. Chances they are. I am - not by any script, but nowadays with some spare time i have been checking sg in such regular intervals it is repetitive, without thinking and too regularly, even more so when im playing- i rarely play for too many hours at once, so short play sessions, and what site i open between then? Can you guess?

It certainly looks automated- it looks so to me (and constantly make me question if its healthy). But the cause is the nature of the site, how points are generated and how users can make gas as short as one hour.

Also twice i had wins that took long for me to receive because the gifters were still to buy then; It may have been more then twice, its only that in those two instances i was told so.
One i received, one i didn't- the gifter, also a friend on steam, missed out on the deal he would get the game and was trying to find another to avoid a unsent gift.

Im way more worried by what i see like true problens that i feel aren't well adressed- like user with a couple (or many) unactivated wins just getting a suspension or the use of scripts - and on scripts, not receiving your win asap gifter online or not is no 'proof' of scripting, frankly.

I'm often away from my computer for 2-5 days at a time. SG is my start page on my phone browser, so each time I check something on the internet through my phone, my SG account will show as logged in, even if I haven't been on my computer for days. I would however leave a message to the giveaway creator saying I would be out for a few days and not able to activate the key until I'm back, just so they knew.

It might be that the user that won has a somewhat similar situation, and maybe even missed the win notification/doesn't have time to check right now.

Just saying that "logging in to SG all the time without being online on Steam" doesn't have to be something weird. But yeah, unactivated wins always gives mixed feelings...

It appears I was abit impatient.

(I don't know how to edit my first post)

Dude marked it as received about 30 mins ago and it's activated on his steam account, even though it still shows 3 days since last login (meh).

Thanks for the input, am still open to advice as to what to look for if something raises questions :)

View attached image.

Maybe he is on mobile

assume everyone is a bot and their behavior will make more sense

View attached image.

that is the reason i always contact the winner on steam and write him if he is online. after that i send him the gift. If they cant bother to look i cant bother to give them the key.