Keep in mind that custom metrics & dimensions are also not compatible with cross-environment attribution, but can be used with last click, pre-defined & data driven attribution models across both reporting & bid strategies. Speaking of;
Custom dimensions can be used to define the difference in value between different conversion types. In our education example above, “Business” courses may be worth twice as much as “Health” courses; knowing this, we can create a bid strategy that weights our bids appropriate by first creating a formula column that weights the two course types appropriately (e.g. (2 * c:”business course”) + c:”health course”) and utilise this formula in a Target CPA strategy.
Unfortunately, custom metrics cannot be used in bid strategies. However, separate metrics can be defined via the custom dimensions.
For example, an international travel company accepts purchases in a variety of different currencies, which are identified with a custom dimension, but want to estimate overall revenue in a single currency. These can be separated in the column creation by selecting the transaction Floodlight, defining the metric as Revenue, then using the Custom Dimension Filter to specify the string associated with a currency. After each currency has been separated, we can use a Formula Column to apply appropriate exchange rates to each and combine, resulting in a rough, consistent revenue that can even be used in a bid strategy.