{
    "_id" : ObjectId("5a137c6e264a81b4cb09c667"),
    "kpi_at_date" : [
       {date: ISODate("2017-07-03T21:00:00.000Z"), kpi: {search_count: 3, click_count: 3} },
       {date: ISODate("2017-07-03T21:00:00.000Z"), kpi: {search_count: 4, click_count: 8} }
    ],
    "channel" : "blah",
    "searchterm" : "searchterm"
}