Sometimes you may have a very large file or you want your contacts in different groups. Click2Sell supports groups on the upload.
Simply add an additional column to your spreadsheet. Label the group names anything you want. Then match that column to group_name in Click2Sell.
Your contacts will be uploaded to the different groups. Note, you still have to pick a default group (like no campaign) but only contacts that do not have a group name will be loaded to the default group.