It's remarkable how many Google services Internet users have grown to rely on: the search engine, language translation tools, maps, email and news alerts. Many online sellers send feeds to Google Product Search and use Google's advertising tools. This month, Google added two more tools that are bound to be popular with its users, and these tools could help online sellers save time and money.

Last week, Google added the ability for users to call regular telephones from their Gmail email accounts for free in a service similar to Skype. Previously calls from Gmail Voice and Video Chat were limited to calls to other Gmail accounts - computer to computer. Voice Calls from Gmail let users call landlines and cell phones, and will be free to the U.S. and Canada for at least the rest of the year. International calls incur fees.

Google launched another tool on Tuesday that promises to help with a problem that every online seller has - too much email. Priority Inbox launched in beta and is designed to identify important mail and segregate it into its own folder. Google explained, "In a way, Priority Inbox is like your personal assistant, helping you focus on the messages that matter without requiring you to set up complex rules."

As messages come in, Gmail Priority Inbox automatically flags some of them as important. Gmail uses a variety of signals to predict which messages are important, including the people you email most.

With the amount of mail that online sellers receive on a daily basis, Gmail's Priority Inbox is worth investigating.