Follow them on your social media accounts,then like and leave comments to grab their attention, something like...
"Always a great time with #Dailygoodiebox!"
Or
"We love buying products like these"
Etc...make your comments stand out,and hype it up and seem really excited,and when you leave comments,always say something positive about them,also,leave colorful emojis to stand out,so that way you will be noticed more than the others,and you will have way better chances at being chosen for a box,for some reasons that's what seems to work for me,but be fast when they tweet it or post it on Instagram, Facebook etc...and always check keep your eye out for when they post on all social media platforms announcing that they have a giveaway happening. These ways helped me get my boxes,I hope this helps

Comment on the daily posts they do on fb and twitter