And decided to stick with double opt-in- because:
Double opt-in system will protect you from spam complaints, at least to some extent. With the current increase of anti-spam legislation, double confirmation may soon become the only safeguard against being blacklisted by anti-spam organizations.
Quality of list will be higher, because at least they took some of their time to go through your confirmation process.
The major complaint people have about double opt-in is that they don’t get as many as subscribers as they would get in single opt-in.
In my experience 20% or more email addresses get from single opt-in could be worthless anyway. Why?
1. There is a chance that people may mistype their email address. Even if they enter the correct email, they don’t really use that email often because their only intention is to download your freebie on your thank you page.
2. People may subscribe friends or family, who may not want to receive your messages and who could, in the worst case scenario, accuse you of spam.
In other words with confirmed subscriptions you are basically dealing with people who have given you valid email addresses they actually use. If someone won't even give you a real email address do you think that person would bother to buy from you?
I tried several methods to encourage people to confirm their subscription, the one really worked is, offer some sort of incentive for them to do so. But you don't want to make that incentive available on your thank you page.
Your incentive MUST be sent only to the people who take the time to confirm their subscription. Make that known.
Do you still prefer single opt-in?