The web is overflowing with how-to guides on running a Facebook ad campaign.

If you're running an ad campaign yourself, it might be useful for you to get a sneak peak from inside an ad agency. AdvertiseMint shares their top 7 lessons.

1. Re-marketing or re-targeting ads should be a top priority

Most people think of running a Facebook ad to gain new customers, when they already have thousands of people who have visited their site and have yet to purchase a single item.

Setting up a re-marketing campaign on Facebook to target the people who already know you exist is the first and most important step. This should be the first type of Facebook ad you run.

Brian Meert, from AdvertiseMint, shares, "These are usually the people that are most likely to purchase. To implement, you need to add the Facebook pixel to your site and then set up a custom audience."

What is a pixel?

The Facebook pixel is a piece of JavaScript code for your website that enables you to measure, optimize and build audiences for your ad campaigns. Using the Facebook pixel, you can leverage the actions people take on your website across devices to inform more effective Facebook advertising campaigns. You can read more on Facebook pixels here.

2. A lookalike used is a dollar saved

What is a lookalike? Facebook has this thing called a "lookalike" audience.

For example, you have the ability to create a pixel that captures all the users on your site you have added a product to their cart and have not checked out. Also known as cart abandonment.

In this case, you can create a lookalike audience where Facebook will find Facebook users who look like the users on your site that have abandoned their cart. This allows you to gain new exposure to people who look like the people who are already visiting your site and were interested just enough to add a product or two to their cart.

Meert tells us,

"Over the past year, we've seen Facebook give a priority to targeting that is based within Lookalikes. So if you are looking for a specific person, add your targeting inside of a lookalike to save some money on your cost per bid."

3. Talk with people, not at people

If there is anywhere you should be engaging with people, it's online. The old school advertising methods of outdoor billboards and bus stops might have been a good platform for sharing your brand slogan or message. In today's digital world, sharing your slogan is not going to cut it.

Social media is exactly that, social. This space allows you to start a conversation. Imagine you are walking into a party, only the party is someone's Facebook feed. Don't attack them with an aggressive message, instead give them tiny bits of information that will keep them engaged and start a conversation. Flirt. Be human in your text and captions.

4. Engage in trending topics

Meert says, "Facebook has their secret sauce when it comes to how to show ads. If your topic is controversial or a hot topic, you will often see tremendous results with your ads. The easiest way to find these subjects is under the What's Trending section on Facebook."

Stay on top of trending topics until it is relevant to your product or brand. Trying to engage a trending topic for the sake of doing so when it doesn't make sense can also be a poor representation of your brand and goes against tip 3 about staying in an authentic human conversation.

5. Watch your frequency

Your magic number is 5. Once you hit a frequency of 5, your cost per click and actual results will begin to decline as users tune out your ads, thus decreasing your relevancy score.

6. Relevance score will save you cash

Relevance score is a number between 1-10 that is determined by how much positive and negative feedback you get from an ad. When your ads have a relevance score of 10, it means Facebook users are finding your ad relevant, and thus, making Facebook more relevant. Facebook rewards advertisers with reduced bidding when this happens. Bottom line... keep trying for that 10.

The way to keep your ad relevancy score high is by considering your audience, the time and platform that you are placing your ad bids on and the content you are using. One thing to keep in mind is that you want to be specific with your audience. Don't be afraid to use the exclusion option. You can exclude a specific segment of an audience to make your ad more relevant. For example, you can select to target all women in a specific geographic area between the ages of 20 to 40 and exclude women who are between 29 to 31. The more you match your content to your audience, the higher chance you have at getting a good relevancy score.

7. Facebook will take your money if you don't know what you are doing

Meert shares,

Many clients come to us with their ad campaigns when they make the realization of "we might not be running these efficiently". The sad part is that they've typically wasted thousands of dollars without knowing it. By default, Facebook will run your ads across their entire network, which includes Instagram, Facebook Right Column, Instant Articles and Audience Network. Not all of these are profitable for every business, so you'll need to monitor and remove the placements that are not generating you results.

Every time you come across an option or category on the ads manager platform that you are not familiar with, become familiar with it. Ignoring one step can cost you. For example, Facebook often has 'advanced options or settings.' Click on it to expand and open those up. Make sure they are set up to be relevant to your ad. Every setting option counts.