Why do we recommend using the auto bidder? Because it dynamically adjusts bids to ensure traffic from each site and combination of parameters you target (for example, Site — Carrier — Placement — Creative combinations, and so on). Go2mobi’s auto bidder aims to bid enough to win around 40% of auctions it enters. Using the auto-bidder will not restrict your campaign's traffic around a static bid CPM. It allows you to win impressions across traffic that is priced at many different levels; thus giving your campaign the best chance to find the profitable pockets.
Standard Bid is setting a static bid CPM that will bid the inputted price level across all placements being targeted.