Not every metric can be combined with every dimension. Each dimension and metrics has a scope: visit, action and conversion. The scope of a dimension and metric can be different, it only makes sense to combine dimension and metrics that share the same scope. For example: Visits is a visit based metric, so it should be used with a visit-level dimension like Browser or Country. If you combine Visits with a action level dimension like Keyword (Site Search) then the logic doesn’t align. This may result in you getting totals which don’t align. For a list of dimension-metric pairs, see the following list

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