Don't do solo ads dude, those are just regurgitated free-seeking-products people.
Usually those leads come from emails that give them the world for free, which are NOT buyers.
Want buyers in your list? Try PPC, Social Media or Media Buys.
Add follow ups to your new subscribers and watch the money rain.
I'm working in social atm and its working decently, I will scale this to 10k subscribers and $$$$ will come easily.
You probably don't know how email marketing works.
let me remember you something, All people are buyers under the right conditions,time and offer.
Now,if you get their email and the next day say ,hey ,here is a cool product,buy it ,then it's obvious you're going to fail.
Think about this,if you give me your email today because i told you something and tomorrow i send you a promo email,would you buy from me?
Now think about this,you give me your email because i told you something useful about seo and every day i send you useful informations about seo,case studies ,strategies etc. and once or twice a month i say to you: Hey this cool product about seo is so great.It helped me to rank on page 1 of google,go and check it.
In which case you're most likely to buy ?
P.S my list is at 150 subs and my open rate is 30 percent on first follow up email and 15% thereafter. (I send them email daily) Think having 10,000 subs in a list.
P.S.S OP,never hear what others say,until you have proof for yourself,never believe anything.