PPC Data Analysis For Seasonality And Externalities
Tags: pcc externalities, ppc seasonality
When analyzing PPC campaign data, have you come across difficulties in analyzing the data to
1. determine if the data has seasonality and external factors
2. how to adjust the data for seasonality and external factors
Often when we analyze Adwords PPC campaign data, we have to ensure that the data is free from seasonality and other external factors before we determine how we can improve the performance of PPC campaigns. I will try to share the simple methods i use which you use to analyze the data.
Always start by understanding your client business, the products/services, their target market, any new products they have released, their offline marketing initiatives etc. before proceeding to analyze data. Depending upon the type of business and what you are intending to achieve, you can choose the time period (months,1 year 2 year) and the specific metrics to analyze. If you are looking at determining seasonality, then it’s good to compare data across more than one year as it helps identify trends, ensures you are not looking at one time spikes caused due to offline promotions, product releases and other external factors.
Method 1
The easiest and simplest is to obtain the weekly or monthly average number of conversions from the client and compare it with the actual data set for specific time period. For example if the average number of monthly conversions is 250, then compare it with the actual number of conversions for the specific time period. The best is to always use graphs as it makes it easy to spot trends, seasonality and other external factors in the data. Once you have spotted trends/seasonality/external factors, then select the data for that specific time period and analyze further to determine the cause of it.
Method 2
Calculate the averages of data set for specific time period you have selected and divide each data point by average and multiply by 100. The data column “(Conv./Avg.) X 100” shows by what percentage is each month’s conversions big or small corresponding to the average. You can use it to determine which months are higher and which months are lower. Once you have the data, analyze and determine why some months are bigger and some months are smaller and some months are same as the average.
Method 3
Calculate the average for the whole year and subtract it from each month’s conversion data. The data column “Conv.-Avg.” shows the difference between the monthly conversions and the average and whether it’s higher than the average or lesser than the average. If it’s negative, the monthly conversions are fewer than the average by whatever is the number. If it’s positive, the monthly conversions are larger than the average by whatever is the number. Once you have the data, analyze and determine why some months are bigger and some months are smaller and some months are same as the average.
Conclusion
The only difference between method 2 & method 3 is the data unit format. You can choose to use either one of the methods depending upon your preference. Now by looking at the data from the table in either Method2 or 3, it’s clear that months 11 & 12 have significantly large number of conversions. Now you need to determine why there is such a big difference and if it’s due to seasonality, other offline marketing promotions, external factors etc. These are simple ways to start analyzing the data. I will write a follow-up article on how to adjust or normalize data to remove seasonality and external factors.
Pitstop Media offers ROI based internet marketing services. If you need help with PPC management or PPC optimization please contact us for a free, no obligation quote. We’ve helped companies reduce their paid advertising cost by as much as 48% and increase AdWords conversion rates by as much as 410%. See our internet marketing case studies.







Megan said:
Oct 28, 10 at 1:33 pmBut don’t all internal factors (bids, ads, keywords etc.) need to remain constant across the entire date range for the results to be “true” results?
Sahaj said:
Oct 28, 10 at 3:02 pmHi Megan,
Good question. In most cases we look at client’s analytics and adwords data for 2 years or more. This allows to confirm external factors (trends/seasonality) rather than internal factors as mentioned by you. If yearly data don’t follow same trends, then we look at why there is an increase/decrease during certain periods in a year, bid, ad, keyword changes as well as other external factors like website changes, marketing promotions through other channels etc. You can also analyze the data to factor for the internal changes before analyzing seasonality, but in general there are too many changes to factor and hence we don’t use it often.
ravema said:
Dec 15, 10 at 4:25 amHow one can compute seasonality in yearly data(not monthly data)?
What is the method to overcome this problem?Please answer to this question quickly.
wajiha nasir said:
Dec 16, 10 at 11:43 pmhow can we deal with seasonality in annual data?
Sahaj said:
Dec 17, 10 at 1:50 pmRavema – I didn’t understand your question “How one can compute seasonality in yearly data(not monthly data)?”. Analyzing seasonality is actually variance analysis. So you should be able to break the data in to months or weeks or days to analyze. Only then you can compare and identify variance. So just comparing years, i don’t think you will get lots of valuable information.
Wajiha – What do you mean by “how can we deal with seasonality in annual data?”