Contributor
Posts: 33

# How to test a marketing effect?

Suppose a company has retail stores in two regions, A & B and ran a marketing campaign in region B for 3 months.

The average monthly store sales of last three months BEFORE the campaign of A is 5% higher than those of B.

The average monthly store sales of last three months AFTER the campaign of A is 8% higher than those of B.

I would like to know how to test 8% is significantly higher than 5%.

Contributor
Posts: 33

## Re: How to test a marketing effect?

suppose the data look like below and month 1, 2,3 are before the marketing campaign and month 4, 5, 6 doing marketing campaign.

region, store#, month, sales

A, 001, 1, 100

A, 002, 1, 102

....

B, 101, 1, 67

B, 102, 1, 105

....

A, 001, 4, 99

A, 002, 4,110

...

B, 101, 4, 105

B, 102, 4, 121

....

Super User
Posts: 11,822

## Re: How to test a marketing effect?

My first question would be: did the marketing campaign affect the sales in B? If so by how much?

And instead of worrying about the 5% and 8% difference I would look first if the mean sales in A changed significantly regarless of what happened in B.

There is a time factor here as well. By any chance was there a similar change in the ratio of sales between A and B the same time last year?