Tactic Bid Ranges:
Base Bid: A base bid is the standard bid you want to make on every impression, before any bid factors are applied. Your base bid should take into account the size of your audience and the scale of your targeting -- the smaller your scale, the larger your base bid should be.
Max Bid: A max bid is the largest bid you want to make on an impression, after all bid factors are applied.
Why is the CPM higher than my max bid?
Your max bid applies to media cost only. The final CPM may include platform or partner fees.