1. A computer-implemented method for identifying advertising opportunities, the method comprising: processing a quantity of query instances received during a first time period and a quantity of query instances received during a second time period, each of the first and second quantities of query instances having a respective impressions per query instance value, to calculate (a) a volume differential between the respective quantities of query instances, (b) a percentage differential between the respective quantities of query instances, and (c) a volume differential between the respective impressions per query instance values, each of the query instances received during the first time period and the query instances received during the second time period corresponding to a specific search query; receiving a selection corresponding to at least one of (a) the quantity of query instances received during a first time period and (b) the quantity of query instances received during a second time period; computing, with a processor executing code, a first opportunity index, the first opportunity index comprising a product of: (a) an absolute value of the volume differential between the respective quantities of query instances, and (b) the percentage differential between the respective quantities of query instances; computing a second opportunity index, the second opportunity index comprising a product of: (a) an absolute value of the first opportunity index, (b) the volume differential between the respective impressions per query instance values, and (c) at least one of the impressions per query instance values; providing one or more campaign improvement suggestions to an advertiser based on the second opportunity index; generating one or more reports reflecting at least one of: (a) the quantity of query instances received during the first time period, (b) the quantity of query instances received during the second time period, (c) the impressions per query instance value of the first time period, (d) the impressions per query instance value of the second time period, (e) the volume differential between the respective quantities of query instances, (f) the percentage differential between the respective quantities of query instances, (q) the volume differential between the respective impressions per query instance values, (h) a percentage differential between the respective impressions per query instance values, (i) the first opportunity index, and (i) the second opportunity index, for one or more of the plurality of different search queries; and providing the reports for display.