The feeling you need a list to start a marketing campaign is unfounded. Waiting to build a list, then trying to sell something to that list is a mistake. You need marketing assets, these can take the form of a Book, Webinar, Case Study Report +++.
Your potential customers are looking for education from you, if you want to increase your opt-in rates from your web site then provide education first, use strategic copy writing, and measure the consumption of your education by your engaged prospects– those are your hot LEADS.
If they dont respond then contact them again, there is no risk of burning out your list to those that have not opened your emails.
Find out more about this strategy that could be become the most effective tool you have: