Adding instead of sending over E-Mail

because i secretly love you.

Why not? XD

I do it because in the end it's the same thing, except this way you interact with the user before sending the gift. (once he accepts the email gift, he automatically gets added to your friend list)

To make sure they mark as received.

and also some ppl give away gift games from steam that are bought as gift so there is no code to send per mail

If this is a public giveaway, it's probably to check if the winner has a private profile and confirm if he owns the game or not.

Add as friend is more personal. i made only good experiences. and with most of them i am still in touch :)
And last time a winner got hacked on his e-mail adress. ;)

it´s easier to talk to you in the steam chat, making jokes giving you a torrent link and request immediately that you mark it as received.....ribbit?

when the GA is a key, then the email is enough, but if it's a tradable steam gift, then maybe add or trade offer
EDIT: but i always prefer sending by email, i also do this with untradable steam-gifts

Maybe because if it is Steam gift sender will be added to your friendlist automatically?)

Chatting on steam creates an instant connection, although sometimes it's disappointing...

Because sometimes I forget. Plus, I like trying to make friends :(

Adding is a bit safer and also more direct and easier for communication. If the user has made a mistake in their email address, if the address is compromised or if there are any mistakes while sending, it will be messier.

Adding makes sure the game goes directly to the right person and you can directly chat with them while sending the game over and make sure they mark it as received soon. You can also make sure they do not own the game already and that they do not seem like iffy accounts you might want to blacklist in the future. You can also save proof of that interaction along with the gift history in case there is ever a problem down the road.

Perhaps sending through email on Steam works the same way as sending to the username, but I prefer this way anyway.

I prefer handing over the game personally to make sure everything goes smoothly.
A few reasons:

1. In case the key isn't valid
2. Make sure the winner marks the giveaway as received
3. Make sure that the winner is still actively using Steam/Steamgifts (it doesn't happen often, but some people win games and then forget about Steamgifts entirely)

I had a few problems with people not accepting friend requests. And I found that you can send it to an e-mail and it doesn't stop you from choosing 'send gift' again and sending it somewhere else if for instance someone does add you as a friend. And since then I just reply to people when they say 'thanks for the giveaway' or whatever and say 'I sent you the game by e-mail, if it is a problem add me on Steam' - and so far that has worked fine for me...

Some of us use e-mails for business/professional/etc purposes only, and communicating through Steam is easier, more secure, and less invasive.

Add in the other benefits noted above by others, and the real question is: Who prefers to e-mail, except for the benefit of not having to actively chat with the person [you anti-social person, you]?

Edit: Bonus benefit, you don't have to dig up the person's e-mail address, you can just straight and simply connect to them through the site.

There seems to be some indication above that it's possible to e-mail through Steam, but let me assure you, that's not an e-mail that will ever get checked.

Email as in case he does not verify that he received the gift, i will have proof that i sent it to him

I prefer none

If you add them, then you can ensure that they received the key. If you send it to a random e-mail, they could have typed it incorrectly, it could have gone to their SPAM folder, they could be hacked, many possibilities that I'd rather avoid.

I prefer mail when I send - I don't care when I recieve.

I like to add the people that win my games no matter if it's a steam key or steam gift. I like to communicate with the person. Make sure they don't already own the content, make sure they redeem the key/gift and mark it as received. Also so they can show their gratitude.

It's just a matter of preference. :)

I add for reason: emailing gifts shows my email to correspondents. I don't need that, at all

E-mail, because i don't know if they will like me or if they even like me so i rather have on my steam people to have a nice friendship :3

I like adding them so they can say thank you instead of just receiving it...