Social media content that engaged restaurant customers the most last month had more to do with brand-specific contests, giveaways or anniversaries than Father’s Day and graduation season promotions, according to the NRN Social 200.

The NRN Social 200 is an index that monitors and measures the social media success of the Top 200 largest restaurant brands, based on Nation’s Restaurant News’ annual census of brand U.S. sales. NRN has partnered with social media tracking and analysis firm TrackingSocial to create the index, which explores the engagement level and relationship between the largest restaurant brands and their social media audiences on Facebook, Twitter and YouTube.

During the month of June, NRN tracked the brands making the largest leaps in overall Social 200 index scores from week to week. Here’s a look at the social media trends that surfaced during the month.

No contest: Contests work

Papa Murphy’s Take ‘N’ Bake Pizza had the month’s biggest gain on the Social 200 Index, recording an 88-percent jump the first week of June, following its May 29 announcement of its Take ‘N’ Grill Sweepstakes.

Because Papa Murphy’s derives most of its social-media influence on Facebook, the chain’s growth in “likes” was especially significant. In a June 1 post, Papa Murphy’s shared that its Facebook page earned more than 30,000 new likes in the first three days of the Take ‘N’ Grill contest, which accounts for more than 11 percent of the page’s nearly 260,000 total likes to date.

A smaller chain with a smaller base index score, Marie Callender’s, also brought about large gains in social engagement in June with a contest, which doubled as an anniversary celebration. The family-dining chain’s 65th birthday sweepstakes, which offered a $150 Amazon.com gift card as the prize, drove gains in Marie Callender’s Social 200 index score of 17.9 percent and 17.3 percent, respectively, in the first two weeks of June.

Quick-service chain Culver’s also increased its engagement steadily in June, including a 9.4-percent weekly gain the fourth week of June, on the strength of two contests: the ButterBurger Photobomb contest on Twitter and the Share the Love sweepstakes on Facebook.

In the former, fans were asked to upload pictures on Twitter of people getting “photobombed” by the chain’s burgers and to mark them with a special hash tag. The Share the Love sweepstakes promoted Culver’s featured frozen-custard Concrete Mixer for its current marketing window, made with Reese’s Peanut Butter Cups.

Culver’s Facebook page surpassed 500,000 likes on June 17.