SAN FRANCISCO (AFP) -- An update to Google's free online map service now lets users become local guides who post reviews of businesses and venues, in a challenge to Yelp.

Local Guides, launched Friday, was described by Google as a global community of the top reviewers who reap benefits based on how much they post about businesses they visit.

Perks promised Local Guides ranged from access to a monthly news letter to being featured on the Internet titan's Facebook, Twitter, and Google+ pages along with being sent an annual gift for "high-quality contributions" to Google Maps.

The move came as a challenge to "Yelp's Elite" program that rewards people for getting into the upper echelon of voices at the crowd-sourced reviews service.

Facebook last month launched a new feature that automatically provides tips about places where members of the social network might be, potentially challenging Yelp and other review websites.