I got one too. I just politely responded that it's banned to Sub4sub now, and invited the person to read and enjoy my novel. But that I wouldn't be subscribing.
I have been enjoying going around on my own, and looking for similar reads to my novel and genres that I like. You don't really need to Sub4Sub out there. There are plenty of good stories to subscribe to and follow without doing the Sub4Sub. I have found some pretty good stories that I look forward to reading each day. I like doing that to get a feel of what is out there and what people like to read on the platform. It helps as a writer. I really don't like being compelled to subscribe unless I like the story. Besides, it helps as a writer to read your own genre and find what else are comp stories to yours. So, it's a relief to see this was banned. Organic reading as a writer is so much better, and doesn't give you empty read stats.