Update 11/25/2014: With the help of CallRail, we have written a new, expanded and authoritative guide to Call Tracking for Local.

The question of call tracking keeps coming up in local search. Should it be used? Why or why not? The answer is often posed in stark terms of either you should or you shouldn’t use call tracking.

The reality is, as is usual, more nuanced and subtle than that. It is a technology that has incredible power but that is easy to use improperly and when done so it can cause on-going problems in local and a great deal of damage. All too often it is suggested as a tactic to unsuspecting businesses by companies that offer little of real value and use the technique to take credit for calls that the business would have received any ways. Often these businesses are not made aware of the disasters that can possibly ensue.

Given that the first dictum of search optimization is (or should be) do no harm it is easiest, when given 3 minutes to answer the question, to say that call tracking should not be used.

What harm can come of using call tracking numbers? There are actually several situations that can lead to long term problems.

The first is that Google assembles all local listings via a machine. That machine looks to match name, address and phone number of information it finds across the internet with a cluster of similar data about a business. If the match is made with data that Google finds across the net and the cluster, that business is credited with that citation. If it is not possible for the machine to make the match due to the fact that a call tracking number is being used then it is possible that Google will create a new cluster for the data. Not only is a given listing NOT given credit for a citation but it is possible that dupes will appear that will “steal” strength from the main listing. Effectively phone number is the glue that holds the cluster together. If the cluster becomes unglued your listing will very likely rank poorly at Google and it could take months to do the recovery work necessary to make it whole again.

Secondly, call tracking numbers are frequently “loaned” to a business for the duration of the contract and then put back into use for a different business. Unfortunately these numbers are very persistent in the online local ecosystem and may stay at various sites attached to your listing. If the number is no longer in your control it means that the customer attempting to call you will be getting through to some business but not yours! The solution to this issue is simple: NEVER use call tracking numbers if the numbers can not be transferred to you at the end of the contract.

The subtler answer to whether call tracking numbers can be used is that they can be in some very limited ways but the guidelines to proper use are complicated and they need to be implemented in such a way as to not cause damage. If the guidelines can not be followed to a T then it is far better to not use call tracking at all as the damage will far outweigh any benefits.

There are four places that a call tracking number can be used:

– Offline

– On your Google+ Local Page

– In the local ecosystem of IYPS, Yelp, CityGrid etc (i.e. any place but Google – APBG)

– On your website

Lets look at these use cases one by one.

Offline at first glance would seem an obvious place where call tracking might just work. It is actually though the least controllable and difficult to predict where the numbers might show up. For example InfoGroup scans printed Yellow Page directories quickly leading to duplicate listings at Google. Yipit for example enters coupons from the print media. Thus it is very likely for a call tracking number to end up online sooner or later and when it does, it will cause havoc.

Can a call tracking number be used successfully offline? Yes but only if you always use the exact same number AND you add it to your Google Places for Business dashboard as a second number (like you would an 800 number). While its value is limited, at least then Google will be able to keep the data associated with your main cluster (assuming that all the other data like business name is correct as well). My assessment? Probably not worth the tracking gain and you would be better off tracking incoming calls manually.

Google+ Local is a no brainer in not being good for a call tracking number. Adding a call tracking number in the dashboard as the primary number may instantly create a duplicate listing at Google that would likely not ranking very well. Even if Google doesn’t bifurcate your cluster they are likely to override your call tracking number with your local number in search results because it is the more trusted number. The only option is to put the call tracking number at Google as a secondary number. Why would you want to do that when it will likely never be seen? So as to allow the cluster to capture the citation from the local ecosystem if you used it there….

The local ecosystem is where implementing call tracking can cause the biggest problems with Google. The data moves around the ecosystem in opaque ways and can be persistent there for years after a number’s use has been discontinued. While we have some idea which sites Google uses as primary resources for additional listing data we don’t really know them all. An errant number in the local ecosystem is very likely to both reduce the strength of your main listing at Google AND cause a duplicate record to show there. The ONLY technique that can work is to use a SINGLE call tracking number as the primary number across the ecosystem and your local number as a secondary number across the ecosystem. Then be sure to add that call tracking number as a secondary number in your Places Dashboard.

Obviously this will only give you the benefit of tracking the APBG sites as a group. Given that they generate so little total traffic I am not sure that is such a good a idea. Much of the traffic generated at these sites is from branded searches that you likely would have received any ways. But it use does provide some additional detail.

Worth the effort? Certainly not if it is done wrong. And most of the campaigns that I have looked at from the likes of Dex and Reachlocal have been done improperly.

On your website is one environment where you have more control and might see some interesting value to using call tracking numbers. But even there if not done properly it can cause immeasurable harm to your Google local results. Google uses your website as the authoritative document in tracking your location prominence. Once again the phone number is a critical glue to being sure that the correct site is associated with the correct cluster. Thus it is critical that Google always see your correct local number when they visit and scrape your site.

How can this be done with call tracking? A simple way is to use an image file showing a tracking number writ large to a visitor while being sure that a plain text version of your number is visible to Google in the footer of your site. Another technique would be to use a java script to display a tracking number to the user but that guarantees that the Google bot and searchers from Google always see your local number. (See this discussion confirming that this practice is acceptable). Even in that situation I would be sure that the footer number and contact us page number accurately reflect your real local number so as not to confuse the Google’s cluster.

Alternatives: If you don’t have the resources to implement this correctly you are likely to cause more damage than good. A preferable alternative to screwing up your Google listing would be track incoming calls manually by asking the caller. Not as accurate, not as easy but a whole lot better than hosing your Google listing (which is likely returning the vast majority of your new inquiries anyways). Whitespark has this offline conversion tracking form that might be able to make this process easier.

The Bottom Line (updated to reflect some great comments):

Offline & Google Places for Business Dashboard: Use with great care. If the location of the tracking number is absolutely 100% guaranteed to not show up online and not be visible to Google then use with abandon (ie a billboard) but if there is any chance that the data will be scraped like coupons or YP ads then use only one number and be sure that it is also added to your Google listing as the secondary number.

Local Ecosytem: It can really hose your listing so be careful and use only one number and be sure that it is also added to your Google listing

Your website: OK to use if done with careful planning either via a javascript or image files.

And if you do some form of call tracking? Always retain the number for your business and NEVER return it to the vendor.

If the vendor is not willing to follow the above to the letter then either 1)they don’t care about your Google ranking 2)they are looking to just get credit for calls you would have already gotten or 3)they are just plain ignorant. Regardless you should run, not walk away, from their proposal because any gain in intelligence will be more than offset by the loss of leads from your Google listings.