Is this in a given geography?
Is this a seasonal trend?
Have we seen this elsewhere i.e. youtube video searches?
Do we have competitive product launch or an alternate internal launch?
Bug / tool / system uptime
Then I will find out by How much? Is this hockeystick or is this gradual? For how long = 1 month or a year or more?
Google ads revenue is mostly ads
Google revenue = Ads revenue = number of impressions * click through rate * CPC
Figure out which of this is an issue:
– If Impressions went down = explore 1) if we are not showing ads or there is change in showing ads, 2) if there is decline in number of users due to social changes, 3) is there a competitive launch or 4) did we have bug or system downtime affecting this
– If Clickthrough rate is down= this is due to 1) irrelevant or misplaced ads due to internal algorithm changes 2) UX or Layout making the ads invisble
If the CPC is down = Find out 1) if avg $ of bids have gone down, 2) if overall economy is affecting this 3) if number of business advertising on Google have declined