Google has announced a significant decision that will see it cease allowing users to sign up to its Google Apps service free of charge.

In a blog post, Clay Bavor, director of product management for Google Apps, explains that the move is being made in order to focus the quality of the user experience on the needs of paying, business users, with fuller support. However, those that have already signed up for the service for free will still be able to use it as before.

“When we launched the premium business version we kept our free, basic version as well,” Bavor explains. “Both businesses and individuals signed up for this version, but time has shown that in practice, the experience isn’t quite right for either group. Businesses quickly outgrow the basic version and want things like 24/7 customer support and larger inboxes. Similarly, consumers often have to wait to get new features while we make them business-ready. ”

Google is now encouraging users to sign up to Gmail, storage service Google Drive and its other consumer-facing products, instead of Google Apps. Those that do want to use Google Apps can get the premium version, which remains $50 per user, per year.

Google says that the end of the free version will allow it to focus on providing business-grade service, including 24/7 phone support for issues, a 25GB inbox and its 99.9 percent uptime guarantee.

The Wall Street Journal reports that subscriptions to Google Apps and its mapping service for businesses and governments have netted the company some $1 billion over the last year.

Stats-wise, more than 5 million businesses are said to use Google Apps, but the overwhelming majority use the free version. The service — both free and paid — is said to be used by more than 40 million users worldwide.

The move to end free usage makes a lot of sense, and has been much expected, given the investment Google has made in its consumer-targeted cloud offerings, which includes the creation of Dropbox rival Google Drive. The company is also likely to make big changes to Gmail after it hired the team behind much-lauded iOS and Mac mail client Sparrow in August.

The search giant has increased the linkage between the two services lately. Last month it began allowing users to add 10GB of Google Drive files into Gmail emails, and we can expect further alignment of the services going forward.