Lookalike finds similar influencers based on your list of profiles.
Add minimum 15 profiles to a tag. It's important that the profiles are not random. The more they have in commont the better results. For example, from the same city, all moms, all from the same country + your audience.
If you add profiles with 5-10k followers the lookalike result will only show profiles with ... 5-10k followers :)
So be sure to not add random profiles in with wide follower range if you want specific results. For example,
Good example
I'm adding 40 profiles from Oslo, Norway, with 10-50k followers.
Bad example
I'm adding 40 profiles from all over the world, with 10-500k followers.
The Lookalike settings is default to be precise, and optimize for accuracy. However, as there are a limited number of people in this world- you might have to increase the range for broader and less precise results. I suggest you to try different settings to see where your sweetspot is.
To optimize for new profiles, make sure you have the boxes above checked. This will help you optimize for new profiles.
Step 1
Make sure all profiles are from a similar social clique (which means that will be likely to follow other people you're interested in finding)
Step 2
Increase this a little (from Settings)
Step 3
Run Lookalike
Make sure that you find 15-20 (or more) profiles in your initial list that have something in common.
Good initial list: Spend some time finding a good initial lists: examples: 20 students from same school, 20 moms from same city, 20 profiles followed by the same profile (know each other).
Bad initial list: Multiple countries, random follower ranges, no real connection.
How? Manually find 15 profiles and add them to Scope (let's say a group of friends), 15-20 - then run Lookalike.
Try to not run the same list over and over (you'll get fewer and fewer results).
You can also expand the number of Lookalike results through the Settings (shown above). But keep in mind, the best is always to improve the initial list.
If you do like above you'll never have a problem not finding new profiles :)
New profiles are automatically added with Lookalike - Scope adds new profiles connected to your specific audience. Let's say you add 30 profiles in Michigan (same follower range, same audience, same interest) - then the Lookalike list you'll get will be profiles in which many have never been contacted before.
Summary
The more specific and unique lists you run Lookalike on, the better results. The more general and random first lists you run Lookalikes on, the more general and random/bad results.