The code is from official guild wars 2 twitter:
You can get guild wars 2 PoF and/or HoT for 30% off now! (35 $/€ total if you buy both at same time).
Might be worth getting your friends into the game now or just getting that one expansion you thought was too expensive before.
Of course I recommend buying both expansions because Path of Fire is more beginner and exploring friendly, while Heart of Thorn offers more challenging/group content!
How to: Use official buy.guildwars2.com and use code WelcomeToGW2 at checkout.
The code works until June 8th PM 11:59 PM PST
Dont forget the basegame is F2P with bunch of restrictions so you can try the game for a few days to see if you want to buy the expansions!
I cant post links yet, maybe someone fast can link it from the gw2 twitter and do me a favor?