There's multiple changes/test you can do to increase your email conversion rate but making sure you talking to right audience is paramount.
Most providers like Aweber, mailchimp will allow you to have a custom optin/confirmation message and thank you page.
If you look at the graph it has a massive unsubscribe rate, why?
My conversion rate was averaging 4-5% (this is because I'm using general Free Traffic not target ppc/facebook etc)
Now it's 23%., So that's still 77% not interested so I unsubscribe them.
I changed two simple things
1. Give content first before OPTIN confirmation.
2 Provide Bonus Content for Confirming Email their email address.
I give them what the wanted straight up, no waiting for email, no further clicking, they can start reading the report or watching the video straight after they entered name and email address. (Another sneaking trick I use is provide a link to a survey for feedback or any further questions your site visitor may have and the end of the report/video.)
So I follow up 2 more times to those who HAVE NOT confirmed email address, (and haven't had email bounce from there address) then here's the kicker I unsubscribe them!
YES if the visitor has not confirmed there email address within 72hrs I don't waste database storage/ email broadcast for visitors that are not interested I simply unsubscribe them.
I have script that moves the contact from “unconfirmed” to “unsubscribed” and after 30 days I automatically delete the contact from my database, I also do it if they haven't opened or clicked on my emails in the last 180 days too.
Note: I do keep a monthly log of all email transaction for any complaint/compliance issues. simply export to drop box and zip the files.
What most email marketers don't tell you is what do with the 77%. there's not point storing details for broadcast emails as it's clear they are not interested all you can do is follow up replies and add new content/changes based on feedback/surveys.