What's a Solo Ad?
Briefly, solo ads are a form of advertising that allows you to send an email to someone else's email list. And when receiving the email, the subscribers are interested in the information presented, and click on the link included to visit your site.
For example, you want to advertise your site and you give the influencer the link and text with an ad that he will send out. This influencer already has a ready list of subscribers to whom he regularly sends related emails.
The big advantage of that type of email is that the subscribers pay a lot of attention to each email from that particular influencer, and set to buy your product immediately. So, these followers have a high level of trust, as they constantly receive news specifically from this influencer.
This way, the solo mailing is the most effective type of advertisement because it allows you to send your solo ad only to people who are interested, as well as receive only the emails you are interested in, based on your subscriptions.
So it helps to receive only the most important information, avoiding spam. Also, you can use this method as it's handy for finding customers specially in your niche!