A Traditional Marketing Consideration
The Google Forwarding Number is an effective tool for Online Marketing. But, we need to refer back to Traditional Marketing practices when considering this feature, or any Online Marketing capability.
Call Extensions in Google Adwords provide two alternatives. The Online Advertiser can choose to use the actual number of the business to display in the ad; or choose to display a Google Forwarding Number.
Using the actual business number in the ad has limitations regarding, among other things, device reach. The actual business number will only display in the ad if the user is on a high-end mobile device. These are mobile phones that have access to Google.com search, Voice search, Google Mobile App, or Google Maps.
However, the online advertiser can choose the Google Forwarding Number. This option has several advantages, including the ability to display on desktops, tablets, and mobile devices. In addition, there are other advantages such as bid-per-call and advanced reporting statistics.
But, should an online advertiser always use the Google Forwarding Number?
This is a question that only the Business Owner can answer, because the question involves Branding. The phone number used by the customer is at the core of this feature, and a phone number for a company could be as important to the Brand as the Company Logo.
When the user clicks on the number from the online ad to contact the company, the user may also store this number in Contacts List. As a consumer, we like to do business with companies that we have learned to trust. (I often tell the story of when a plumber came into my house and did a great job. I was so impressed, I asked him about a problem I was having with my roof. At first he looked at me funny, then he recommended someone who he knew did roof repair. We want to consult with people we have learned to trust.)
If the user that clicked on the ad stores the Google Forwarding Number in Contacts List, that number may change over time. Google may discontinue or reassign a Custom Phone number (unique Google forwarding number that is dynamically generated for each ad group). So, in the future, the customer may no longer have the correct phone number for the business in Contacts List. This can be a loss of Branding for the company that may be critical to the Business Owner.
When considering implementation of Google Adwords Call Extension, or any Online Marketing capability, discuss the alternatives with the business owner to ensure that the Online Marketing approach is aligned with the Branding goals and practices of the business. The Online Marketing feature that you choose to implement should always be evaluated within the context of the company’s Traditional Marketing goals.
OLinks Corporation - Enterprise Communications 
Great post! I think it’s critical to think about how the newer online media tactics can be mapped back to the traditional tactics that were critical in establishing a customer’s engagement preferences.
In this case, while the technology allows us to engage by “click to talk”, I agree that there are certain habits that people have that may actually affect at how effective the technology is at delivering value to the business.
This can only be evident if businesses put on the “customer” hat and literally (not figuratively, but literally) walk through the experience as the customer would. Only then can you truly understand where to not fix what’s not broken and gain efficiency and advantages through technology.
Good example on the plumber, too. That’s “walking in the customer’s shoes”.