a review of adhesives used by actual scrappers...and a lot more!
The adhesives that I feel would adhere buttons the most effectively are listed here. Buttons can be heavier and need a thicker adhesive to get them to stay where you placed them.
1. Glue Dots-permanent
2. Aleene's Tacky Glue
3. Scotch Scrapbooker's Glue
I have used Duck Adhesive runners on flat buttons, but I would recommend the previous adhesives first.