If you first promote your product on your buyers list and it doesn't convert, then mostly it won't convert on freebie list.
Buyers list is good as you know that they have history of buying and freebie list you are unsure about it.

Just because somebody hasn't bought from you doesn't mean they won't buy from you. Everybody starts out as a freebie seeker at one point. If you are able to provide enough value for your prospect and they are targeted in what you have to offer they will buy from you. People buy from those that they know, like and trust.

A prospect who is on your freebie list that has never bought from you will need a lot of urging before he or she decides to purchase . But a familiar customer with whom you built a rapport or who purchased a sales funnel product during the opt-in stage, already trusts your products and will be more inclined to buy from you again.