There ain't no such thing as a free lunch.
—Heinlein

It happens all across America every day, from metropoles and megalopoles (like the one we live in) to small towns in the heart of farmland: Food-focused social media users ask restaurateurs to pick up their tab in exchange for content.

It's at once the boon and scourge of the hospitality industry.

On the one hand, it gives restaurant owners the opportunity to raise their profile and visibility in the community. On the other hand, so-called "influencers" exploit their position of power, asking for free meals and demanding premium services while misrepresenting their impact and reach.

Few restaurateurs are willing to discuss it openly — for fear of retribution and ostracism. But they are bombarded incessantly by brazen requests for free food.

Whenever you cross the threshold of a restaurant's entrance, whether you are the New York Times restaurant critic or an Instagram user with a handful of followers, you enter into a social compact with the restaurateur, the restaurant employees, and the other diners.

Here are some guidelines intended to make this newly forged model of social interaction a more positive experience for everyone.

Remember that you are the guest — not the paying client — of the business owner.

Whether you have approached the restaurant about organizing a media event or the restaurant has approached you, you are the venue's guest. As the saying goes, the client is always right. But invited, non-paying guests need to be mindful of their social and professional compact.

Tip your servers — generously.

In much of America (although not all of it anymore), the servers make their living mostly through gratuities. You may be enjoying a free meal but the servers still depend on their tips as their earnings. Tip as if you are paying customer. Most food professionals tip even more generously than expected. It's part of the honor code in the industry.

Don't expect free booze.

Beer, wine, and spirits represent one of any restaurateur's greatest costs. Unless the restaurateur offers alcohol, don't expect it. And if you want it, expect to pay for it. If you are attending an event as an influencer, be professional and don't overindulge in alcohol consumption.

Be honest about your ability to influence.

Don't mislead the venue owner/manager or misrepresent your reach and the impact it will have. Are your followers really potential customers for the restaurant? No matter how many followers you have, the impact for the venue will be negligible if you're followers don't regularly frequent similar businesses.

Be up front about what the restaurateur can expect from you.

Are you going to generate content? How much content are you going to create? Are you going to tag the restaurant? Are you going to post negative content if you're disappointed with the experience? Restaurateurs are generally not experts in social media. Be upfront and clear about what you plan to post.

Don't expect to bring guests who are not influencers.

Unless the owner explicitly tells you that you can bring a guest or guests, don't expect to bring one. And don't ever demand that you be allowed to bring one or announce that you are bringing one after you've already agreed on the ground rules for the event or seating.

Be considerate of other people dining at the venue.

The rest of the diners are actually paying for their experience. Be respectful of the servers' and managers' time. The people who work at the restaurant need to take care of everyone in the restaurant — not just you. Don't affect the restaurant's ability to do business by being disruptive or becoming a distraction.

Remember that your reporting can affect the livelihood not only of the owner but all the people who work there.

If you do have a negative experience and feel compelled to share it on social media, be sure that you base it in fact and that it reflects a knowledge and awareness of community standards. One person's meat may be another's poison: Be sure that your criticism is offered in context with what the average diner should expect in terms of quality and service.

Be aware of and don't abuse your position of power.

Instant karma gonna's get you, as John Lennon once sang. The stakes in food criticism are low for the influencer; they are high for the business owner. Don't let a sense of entitlement or privilege be your guide. Don't let your ego drive your content or interaction with other food professionals, especially those who make a living through food.

Be polite to everyone at the restaurant — even the bussers. They are people, too.

Food critics and influencers are food professionals. And they should treat other food professionals — whether bussers, dishwashers, sommeliers, chefs, or servers — with the same respect and courtesy they treat their journalist and influencer colleagues.

The author is a Houston-based restaurant and wine industry marketing consultant and wine writer.