Thread: Help, real increase.

Ok, So say I want to measure the real impact of some marketing on an isolated day/week.

Now because marketing is switched on and off it makes this harder, so what I was thinking is looking at a year on year difference and a versus the previous 8 weeks average difference, as a %.

Eg...
This week we were say 85% versus the previous 8 week average of this year.
But that 8 week average was up 9% versus the same 8 weeks of last year.
YoY this week was up 75% versus last year, but the same week last year was 15% up versus its prior 8 weekly average.

I'm going round in circles here, thinking one of these numbers minus the other is the real impact. I'm just trying to make everything as comparable as possible to get a real idea.

any ideas? HELP!

Or is it say

pre8 week average 2011 comparing week 2011
__________________ ___________________
pre8 Week average 2010 = 100% YoY comparable week 2010 = 167%

Therefore going into this week we were 100% up as a trend, the week in question then performed 167% up on last years comparable week and the difference of 67% is actually the real performance?