Another Starbucks votes to unionize — by a large margin

A third Starbucks location — and the first outside of New York — has voted to unionize.

Employees at a Starbucks store in Mesa, Ariz., overwhelming voted in favor of union membership. After the eligible vote count, 25 workers voted in favor of the measure. Only three voted against the measure. (A second Starbucks store in Mesa has also filed for a union election.)

The ballots will need to be certified by the NLRB's regional director, which may take a week. Then the union will have to negotiate a contract with Starbucks.

The union, Starbucks Workers United, had already won the right to represent workers at two stores in Buffalo, N.Y. The union has also filed to hold additional elections at more than 100 Starbucks stores across 26 states. The number represents a very small percentage of the coffee giant’s nearly 9,000 locations.

[Read More: More Starbucks stores begin move to unionize — in the U.S. and Canada]