Make sure you don't miss any giveaway by subscribing to the discussion page in the group.
You can do this at the right side of this page: http://gtm.steamproxy.vip/groups/pressstarttogiveaway/discussions
the grey button wich says subscribe to.
After you do this, whenever anybody makes a giveaway, you will recieve a steam notification about it in the right upper corner of your steam panel.