[H] Assassin's creed Franchise Pack [W] Tf2 keys,offers

I'll think about it

nah, thanks for the offer

Nah, thanks for the, offer

Not really thanks for the offer

35$ or 27 euros

No, thanks for offering

https://support.steampowered.com/kb_article.php?ref=4502-TPJL-2656 <--- You can find everything here

Users who own "Left 4 Dead" and then go on to purchase "Left 4 Dead + Left 4 Dead 2 Bundle" will receive an extra copy of "Left 4 Dead"
Users who own “Half-Life 2” and go on to purchase “The Orange Box” or the "Valve Complete Pack" will receive an extra copy of “Half-Life 2”.
Users who own “Half-Life 2: Episode One” and then go on to purchase the "Half-Life 2: Episode Pack”, “Valve Complete Pack” or “The Orange Box” will receive an extra copy of “Half-Life 2: Episode One”.
Users who own "Dawn of War II"and then go on to purchase "Dawn of War II Gold Edition" will receive an extra copy of "Dawn of War II"
Users who purchase the available four packs for specific Steam titles will receive three extra copies of that title to gift to friends.
Extra copies may apply as a part of some limited time promotions. In that case, information on what will be included with your purchase will be listed on the storefront's transaction page.

So you'll get an extra copy of them and you can trade them too or send them to a friend
They will appear in your inventory