Allocation system
For each individual visitor, we compute what we call a seed, a unique alphanumeric string that will be persistent in time. This seed, also unique for each campaign, will be used to generate a score between 1 and 100 and then the same logic as before applies.
As the seed is computed each time, we do not need to store the result anymore.
This allocation system doesn't work under the HTTP protocol as we are using cryptographic tools that are only available under a secure protocol.
If the tag detects it is on an insecure environment, it will automatically fallback to the old mechanism.
Use case
Let's take the example of a 50/50 campaign. If a visitor gets a score of 51, they will be exposed to the variant (a score above 49). If you decide to change the allocation from 50/50 to 60/40, the allocation will be computed again and their score of 51 will now place them in the original, as the original is now within 0 and 59. The visitor will switch from one variant to another.
Good to know
Since July 2023, all campaigns are using this traffic allocation system and while this didn't drastically change the way your experiments will operate, there are several changes that you need to acknowledge.
Previously, we used to have a simple yet effective system that was based on a random function. For each new allocation that was needed to do, a virtual dice was rolled and we obtained a score between 1 and 100. For a 50/50 traffic allocation, any visitor with a score between 1 and 50 was assigned to the original and between 51 and 100 to the variant. Each campaign had its own dice roll.
The result of the allocation was stored in the cookie and read by the tag on the following pages. This is how we kept the navigation consistent for a unique visitor.
Set-up
Traffic allocation is the fifth step of the campaign creation flow. When creating a test or a personalization campaign, you need to define the percentage of visitors allocated to the variation(s) (in case of a test) or scenario(s) (in case of a personalization) and the original version of your website.
By default, the traffic is equally shared between the original and the variations (50/50 if there is just one variation plus the original, 33/33/33 if there are two variations, etc.), but this is fully configurable in the test options. You can set the percentage of your traffic that will be allocated to each version.
This table shows the different categories of users, representing your entire website traffic. For each category, information on what the users will see is displayed:
|
🚦 Type of traffic |
🍪 Visitor’s cookie campaign information (ABTasty cookie) |
💬 Comment |
|---|---|---|
|
👻 Untracked visitors |
campaignId=[campaignId] |
Visitors who see the original version of your website but whose actions will not be taken into account. |
|
🎯 Tracked visitors (% of unique visitors of your campaign) |
campaignId=[campaignId] value/variationId=0 or variationID of the variation |
The original version of your website or a new variation/scenario of your website |
|
🏛 Traffic allocated to original |
campaignId=[campaignId] |
Visitors within the test sample who see the original version of your website. |
|
🆕 Traffic allocated to variations |
campaignId=[campaignId] variationId=[variationID of the variation] |
Visitors within the test sample who see a new version of your website (or one of the new versions if there are several variations/scenarios). |
Good to know
As a reminder, it is highly not recommended to change the allocation while a campaign is running. Doing so might severely impact the reliability of your results, even more now with the new system. We strongly advise you to duplicate your campaign and start a fresh new one unless you consider the risk is low (the campaign is still in QA, only a few visitors have seen it until now, etc ..).