What should i do with MANY bundle leftovers ? (hidden ga inside)

I see what you did there...

Train?

http://www.steamgifts.com/giveaways/new

Hmm, not sure if real or trolling.

That was very creative

Please don't link your trade post in the forum.

Trades are limited to the trades section of the site, and should not be posted in giveaways or on the forum.

a plane.

Eat them, they are delicious!

People generally don't trade bundle games. And if they do, expect games for games, or at the very most, trading cards.
If your bundle game is actually in high demand relative to supply (rare, but it happens sometimes) you can try to sell them on third-party sites.
If you find that in the end you can't get rid of it either way, and you're honestly tired of the effort, give them away here on SG.
Not only do people who (hopefully) appreciate them win them in the end, you also gain CV to increase your odds of using this site in general (don't expect too much, but going from your current level 1 to 3-4 ish would greatly increase your benefits of using the gifting portion of the site).
There are private giveaway groups on SG that deal in bundle games where you could win some other bundle games for donating yours.

Bundle games have next to no trade value, unless it's a high-profile game. Trading away something like Bastion is quite doable, but it's not really doable with less high-profile games. Thus your best option, if you want to do something with the keys, would be to give them a nice home through giveaways and such. Why not host an event for it?

It helps if you put a price tag on them. At least it helps me(the consumer).

Create GAs is also an option.
Or you could make it rain keys on the forum! Give it all to ungrateful ninjas!

sacrifice them to our lord gaben, or do like addict people do, make ga's!

I've made some public GA's.
and
I'll be back

You could add your leftover keys to a second Steam account. But read this first since you'll also need to spend the equivalent of $5 in the Steam store to get trading cards to your "real" account. Buying a $5 game as a gift for your "real" account works, adding a $5 wallet code works, but activating gifts or keys do not. Oh, you also have to wait a month before everything's unlocked.

Basically, if you have a large enough pile of leftover keys, making a second account will eventually be profitable for you. But it's not a very big profit. :)

print the keys and use the paper afterwards to burn it in a ofen -> winter is coming
It's no a real answer