Number Pools

You will need a Number Pool configured for your campaign if you want numbers dynamically generated on the landing page for your caller data to uniquely be attributed to calls. Because we are tagging numbers dynamically as visitors reach your landing page, you might need a large number pool depending on the number of unique keyword/ad combinations that you want to track, but limited to the number of concurrent visitors you expect.

Once the visitor calls the number that is displayed, we automatically tag the call with any tags that have been set on the number.

You will need to use one of Retreaver’s two available scripts in your landing page.Our more robust Retreaver.js is our JavaScript library for displaying trackable phone numbers. It offers a flexible API so developers can interact with our services in a way that is both straightforward and compliant with modern standards. It is able to be cached by the visitors browser, and quickly distributed via a CDN.

More on Retreaver.js

If you run low volume traffic and do not require alerts, our much simpler Insert.js will fulfill your needs.

More on Insert.js

Creating a Number Pool

Click on Number Pools / New Number Pool or click here. Basically you have two ways of pulling numbers, ones you pull by doing Number/ New Number, and then ones we generate at the landing page using the Number Pools. The Sniffing Parameters you tell us to look for from the URL are put into Retreaver Tags and attributed to calls.

We ping from your site to Retreaver to know when a consumer is looking at a number. The Buffer Seconds dictates that after they leave, how much longer we hold onto the number/extension. The Max Lease Time dictates how long we let them view it it without calling before we release the number/extension back into the pool. Also once a call is ended, if there are no other users calling the same number, it is released back into to the pool.

A new visitor will reset the timer on the Max Lease Time, but once the Max Lease Time or the last visitor leaves, the number becomes available to be something else later.

Default Number

You need a default number in the source code in order to display to viewers as a fallback when your Number Pool is full. This Default Number is there work alongside the Number Pool. You would add a sub_id Tag for this Number and have it equal ‘default number’ so you know what this number is for in the future. It will be used when the number pool is not sized properly and we need to show a static number from our system. You lose tracking information about why the lander was called, but you won’t lose the call.

Default Sniffing Parameters

To configure your default Retreaver.js URL parameter sniffing settings you have to tell Retreaver what to look for in the URL.These defaults will make setting up new campaigns much quicker, especially if you have multiple levels of sub-affiliates to deal with. To edit your company settings, click Settings, then Company and select Edit at the top.

Default Parameter Sniffing settings.

Once you’ve opened the edit screen, you can choose what keywords to sniff out of the URL and what Tag name you want it to be assigned. In the example below, f_n is being assigned first_name in Retreaver.


Adding a URL parameter to sniff for in Company settings.

How Many Numbers do I Need?

This depends on how deeply you plan to track. You may primarily want to just track back to AffID and SubID. If tracking down to the ClickID, you will need one number displayed per page viewer, which can add up fast. This sort of granularity might be worth the cost in a large pool of numbers. However, if possible, if you can track to fewer keywords then you can ensure your pools will be smaller.

Example 1: If you are only tracking kw=test and 50,000 people are all looking at that keyword, they all get the same number. However if each browser has a different &kw= they will all get a different number. If all kinds of visitors have the same zoneid, they all see the same number. No reason to generate a new number per visitor if you are only tracking that field and it is the same for many visitors.

Example 2: If you send URL Source and SubSource, and in this example you only had 3 sources and 10 subsources, that is only a total combination of 30. So your Number Pool only needs 30 numbers and will track with 100% accuracy.

Example 3: 1 million visitors are viewing a web page and the URL reads This results in 1 million viewers all seeing the same number, since they share all the same tracking data.

In summary, it just depends on how long you set the Max Lease Time in the pool and what you are tracking. If you are tracking down to ClickID, it will be a unique number per visitor, that is how many concurrent visitors you have within the lease time. Try setting the Max Pool Size you think will work and then if we contact you via email saying that your pool is too small, you can either:

1) Ignore it and lose a bit of tracking details.


2) Increase the pool size to track what you want more accurately.

Angela Dougherty

Client Success Officer