From various things I've read, I think a conversion rate around 5% is actually pretty typical, so I wouldn't worry about that. I don't think yours is low for anyone that didn't come with a huge existing audience. For what it's worth, my content was all completely free for ages (and nevertheless quite a few people opted to pay, despite getting nothing extra at all). A few months ago I pay-walled my archive -- posts are free to everyone initially, and remain readable by everyone for four weeks, but for the rest of the archive, only paid subscribers can read beyond the beginning of each piece. Making this switch slightly (but not dramatically) increased the rate of paid subscriptions, and did not lose me free subscribers. I do now occasionally write extra "deep dive" posts which are only for paid subscribers from the start, but when I do this, I don't send them to free subscribers.
From various things I've read, I think a conversion rate around 5% is actually pretty typical, so I wouldn't worry about that. I don't think yours is low for anyone that didn't come with a huge existing audience. For what it's worth, my content was all completely free for ages (and nevertheless quite a few people opted to pay, despite getting nothing extra at all). A few months ago I pay-walled my archive -- posts are free to everyone initially, and remain readable by everyone for four weeks, but for the rest of the archive, only paid subscribers can read beyond the beginning of each piece. Making this switch slightly (but not dramatically) increased the rate of paid subscriptions, and did not lose me free subscribers. I do now occasionally write extra "deep dive" posts which are only for paid subscribers from the start, but when I do this, I don't send them to free subscribers.