from your 'My Snipes' page click on Folders:New on the left. Give the folder a name. Check the box to say the folder is a bid group and then choose the number of items you want - ie how many items should AS win for you until it stops any further snipes. In your case it sounds like you just want one item.
You can then either add snipes direct to this folder or, if they are already lined up in My Snipes, check the boxes next to them and then click on Move to Folder selecting the name of your bid group.
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