Dan Levy, Facebook's vice president for global marketing and small business, said the number of advertisers has doubled over the past year and a half.
"We think it's a strong sign of the commitment we are making to help small businesses," Levy told AFP.
"They continue benefiting the economy for their region and the world."
Levy said the new Ads Manager app would give those advertisers the ability to manage their ads from mobile devices, as Facebook becomes increasingly used on smartphones and tablets.
"This is a moment to celebrate all the incredible entrepreneurs like you who are creating value for their communities," Zuckerberg and Sandberg wrote, citing entrepreneurs using Facebook in places ranging from North Carolina to South Korea to the Brazilian Amazon.
"And there are more than two million other inspiring stories of people working to grow their businesses. You're creating jobs, sharing new ideas and inspiring all of us to dream big," they said.