👥 How to Create and Use Lookalike Audiences for Facebook and YouTube

Here is the simple version. You give Facebook a list of people you already like. Facebook studies them and finds strangers who look like them.

Think about a fishing guide. You show up at the lake and say, "I caught these three fish last week and they were great." The guide looks at your fish. Same kind, same size, same spots. Then he says, "I know exactly where more of those are." He takes you right to them. You skip the hours of casting into empty water.

Facebook is that guide. It knows a LOT about the people on its platform. What they like, what they watch, what they buy, where they live, what time they are online. When you hand it a list of your members, it finds the patterns. Then it builds a new audience of local people who match those patterns. That new audience is your lookalike audience.

The Two Parts of Every Lookalike

1. The seed. Your starting list. Your members, your leads, your website visitors, your video watchers. The better the seed, the better the lookalike.
2. The lookalike itself. The new, bigger audience Facebook builds from the seed. You pick how close a match you want (1% is the closest, 10% is the widest).

Garbage in, garbage out. If your seed is a list of everyone who ever clicked anything, your lookalike will be mushy. If your seed is your 300 members who have paid for six months or more, your lookalike will be sharp.

Gyms are local. Gyms sell to a specific kind of person. And gyms usually have a list of members sitting in their software right now. That is the perfect setup for lookalikes.

Three Reasons Lookalikes Beat Guessing

• They catch things you would never think of. Maybe your members all shop at the same grocery store, follow the same two local pages, and have kids in the same school district. You would never target that. Facebook sees it instantly.
• They get smarter as you grow. Every new member added to your seed list sharpens the pattern. Six months from now, your lookalike is better than it is today.
• They are usually cheaper. Because the audience is a closer match, more people click and more people fill out the form. Facebook rewards ads that get clicked with lower prices.

Pick the Right Seed List

This is the step that matters most and gets the least attention. Your seed is the list Facebook learns from. Choose it carefully.

Great Seeds for a Gym (Best to Good)

1. Members who have paid for 3+ months. The gold standard. These are people who join AND stay. You want more of exactly these.
2. All current paying members. Very good. Slightly less sharp because it includes brand-new joins who might quit.
3. People who bought a challenge or trial. Good. They proved they will pay for fitness.
4. Leads who booked an appointment. Decent. They showed up, but did not all pay.
5. Website visitors (last 90 days). Okay. Useful if you have no other list, but it includes tire-kickers.
6. Video watchers (watched 75%+). Okay for a top-of-funnel lookalike. Good for brand-building ads.

Bad Seeds

• Everyone who ever liked your page. Includes your aunt, your old roommate, and people from other states.
• All leads including the ones who never replied. Teaches Facebook to find people who do not reply.
• A list under 100 people. Facebook needs at least 100 matches to build a lookalike, and 500 to 1,000 works much better.

What to Put in the File

Export from your gym software as a spreadsheet. Facebook matches people best when you include several columns: email, phone number, first name, last name, city, state, zip code. More columns means more matches. Phone and email are the most important. Facebook scrambles the data when you upload it, so it is private.

Build the Lookalike in Facebook

Here are the clicks. It takes about 10 minutes the first time.

Part A: Upload Your Seed as a Custom Audience

1. Open Facebook Ads Manager. Find the menu and go to Audiences.
2. Click Create Audience, then Custom Audience.
3. Choose Customer List.
4. Upload your spreadsheet. Match each column (email, phone, zip) to what Facebook asks for.
5. Name it something clear, like "Members 3+ months, Oct."
6. Wait. It can take up to an hour for Facebook to finish matching.

Part B: Create the Lookalike

1. Back in Audiences, click Create Audience, then Lookalike Audience.
2. For the source, pick the custom audience you just made.
3. For the location, choose your country (you will narrow to your radius later, inside the ad set).
4. For the size, pick 1%. This is the closest match. You can test 2% or 3% later if 1% is too small for your area.
5. Click Create. Give it a few minutes to build.

Part C: Use It in an Ad

1. Build or edit an ad set. Under Audience, pick your new lookalike.
2. Add your location: your gym's address with a radius of 5 to 15 miles, depending on your town.
3. Under Exclusions, add your current member list so you do not pay to advertise to people who already joined.
4. Leave interests blank. The lookalike already knows who to find. Adding interests just shrinks it.

Build the Google and YouTube Version

Google Ads runs ads on YouTube, on Google search, and across millions of websites. It has its own way of doing what lookalikes do. The names change from time to time, but the idea is the same: upload your list, let Google find similar people.

Step 1: Upload Your Customer List to Google

1. Open Google Ads. Go to Tools, then Audience Manager.
2. Click the plus button and choose Customer list (Google calls this "Customer Match").
3. Upload the same spreadsheet you used for Facebook: emails, phones, names, zips.
4. Name it clearly and wait for Google to process it. This can take a day or more the first time.

Step 2: Let Google Expand From It

Google does not always give you a separate "lookalike" button the way Facebook does. Instead, you turn on expansion inside your campaign. Here is where to look:

• In a YouTube or Display campaign: Add your customer list as the audience, then turn on Optimized targeting. Google will use your list as the seed and go find similar people.
• In a Performance Max campaign: Add your customer list as an audience signal. Google treats it as a starting point and expands from there.
• Lookalike segments: Google also offers lookalike segments built from your lists for some campaign types. If you see that option in Audience Manager, use it the same way you would on Facebook.

Step 3: Add Your Location

Same rule as Facebook. In your campaign settings, set your location to a radius around your gym. Otherwise Google will happily find people who match your members in another state.

Use Lookalikes the Smart Way

Having a lookalike is step one. Using it well is where the money is.

Match the Ad to the Audience

Your lookalike is still made of strangers. They look like your members, but they have never heard of you. So do not blast them with "SIGN UP NOW." Treat them like a cold audience that happens to be a very good fit:

• Lead with a real video of your gym and your coaches.
• Make a low-risk first offer: free trial week, $29 for 3 sessions, a 6-week challenge.
• Say who it is for: "Hey [Town] parents..." Your lookalike will mostly BE those people, so it lands.

Test Sizes

1% is the sharpest but the smallest. In a small town, 1% plus a 10-mile radius might only be 8,000 people, which is too few for Facebook to work with. If that happens, try 2% or 3%. Slightly less sharp, but big enough to breathe. Aim for 50,000 or more inside your radius.

Stack Them With Warm Audiences

The best setup for most gyms looks like this:

1. Lookalike (cold, but a good fit): Gets most of the budget. Brings in new people.
2. Warm (video watchers, website visitors): Gets a smaller budget. Reminds people who already saw you.
3. Exclude members everywhere.

Follow Up Fast, Always

A lookalike lead is still a lead. If nobody texts them for two days, they go cold like any other lead. Set up automatic text follow-up so every single person who fills out your form gets a message within 5 minutes: "Hi Sam! Coach Ana from Northside Fitness here. Thanks for grabbing a trial spot! Want to come in Tuesday at 6 or Thursday at 7?" The best audience in the world does not help if the leads sit in a spreadsheet.

Week 1 — Build your seed

1. Export your members who have paid 3+ months from your gym software. Include email, phone, first name, last name, city, state, zip.
2. Export a second list of challenge or trial buyers from the last two years.
3. Export your full current member list (for exclusions).
4. Set up automatic text follow-up so every new lead gets a message within 5 minutes.

Week 2 — Build the Facebook lookalike

1. Upload both seed lists as Custom Audiences. Upload the full member list too.
2. Create a 1% lookalike from each seed.
3. Build one ad set per lookalike with your radius and member exclusions. Same ad, same budget.
4. Launch at $15 to $25 a day total.

Week 3 — Build the Google version

1. Upload your best seed to Google Ads as a Customer Match list.
2. Film a 30-second studio tour with your town's name in the first 3 seconds.
3. Launch a small YouTube campaign using the list with optimized targeting and your radius. Start at $5 to $10 a day.

Week 4 — Compare and refresh

1. Check cost per lead for each lookalike on Facebook. Turn off the weakest, move its budget to the strongest.
2. Check YouTube views, website visits, and leads. Decide if it earns a bigger budget.
3. Check that every lead got a text within 5 minutes.
4. Set a calendar reminder to re-upload your member list and rebuild your lookalikes in 6 weeks.