Now Google has removed this feature. There is no announcement on the official Blogger PR blog, but a Google employee left this message on a support forum stating that the integrated service had been discontinued. There was no explanation as to why this happened, but I suspect the rise of Weebly, Shopify, and other services that offer better-looking websites with integrated domain hosting has reduced the number of people using Blogger with a custom domain.
As far as I know, people who have already registered a domain through Blogger will see no interruption in service, as long as they continue to pay the annual $10 domain registration fee through Google wallet (as I did for one of my other domains last week). But where does this leave bloggers who never had a chance to register a domain in this way?
The good news is, Blogger still supports custom domain hosting in Blogger. The bad news: Users have to register the domain on their own. It's an unpleasant, technical process to not only register the domain but also tweak settings with the registrar that are required to activate the domain on Blogger. In addition, registrars use different terminologies for certain processes, which means it's impossible to give a one-size-fits-all cheat sheet to get it done. But I will try my best to give a general overview of what's required.
Step 1: Register the domain
For the initial step, the basic idea is to find an available domain that no one else is using (for instance, "www.flowercafeboston.com") and claim it by paying for it and giving the ownership details. To do this, you have to go through a "registrar", which are the officially sanctioned companies that are allowed to issue domains and have them connected to the rest of the Internet.
Note that Blogger requires you to have "www." or "blog." in front of the custom domain, in order to be integrated with the service. If you register a "naked domain" (e.g., "flowercafeboston.com") you will get a warning sign. Note that you can add www or something else later, but it's a pain to set up.
The fees for registering a domain are generally pretty cheap -- between $5 and $15 per year is typical, and discounts or special deals are available. However, the registration fee does not include "Hosting", which is basically space on a computer that contain the text, images, and other elements that will make up your website. What we're going to do is use Google's free Blogger service for hosting, but to do that we have to change some settings (described below) on both Blogger and the registrar's website.
Note that after you register a domain, registrars will attempt to upsell other services, including hosting, special website builder packages, and other services. You don't need any of this, because Blogger will take care of that for free. Just find a domain that's available, and register it.
Which domain registration service should you use? Blogger used to be integrated with GoDaddy and eNom. I don't recommend GoDaddy, because the interface is confusing and the upsells are merciless -- it's easy to be tricked into buying something you don't need. For the most recent domain I registered on my own and hooked up to Google, I used 1and1.com. The interface was good, and so far, there haven't been any problems, but that's not a full endorsement.
Step 2: Let Blogger know that you are using a custom domain
Log into Blogger.com, and click Settings. Under Publishing, you will see something like this:
Click the link that says "Add a custom domain".
At this point, you will need to paste in the domain that you just registered on the other site -- for instance, www.flowercafeboston.com.
Step 3: Verify that you own the domain so Blogger can use it
Of course, Blogger will check to make sure that you have the authority to use that domain in its Blogger service, by checking the registration information associated with the domain. But don't be surprised if you get an error message that says "We have not been able to verify the authority to this domain. Error 12":
(I've blacked out some information, for security and privacy reasons)
You'll note that Google provides some technical information to fix the problem. The idea is, you take this information, and paste it into the settings area of the registrar handling your domain registration (for instance, GoDaddy). This is where things get tricky. You basically have to deal with CNAMEs and other tricky settings, and Google's default instructions don't always match up with the terminology used by specific registrars.
In the example above, after I received the "Error 12", I had to go to 1and1.com (my domain registrar) and create two new subdomains for the custom domain (using the "labels" that Blogger cited; in other words create two subdomains called www and cwa62xxxxxx). Then, taking the information under "Destination, Target, or Points To field", I had to copy and paste that into the corresponding "Alias" fields on the 1&1 site for the two subdomains. Under "Use a missing files host?", I kept the default, "No".
Sound confusing? It is. That's why Blogger's decision to pull the plug on integrated domain hosting is so frustrating. If you want to do this, and you are not technically inclined, I highly recommend getting help from someone who is or finding a registrar with good customer service.