As many others here have already stated:
-This sort of thing will turn new readers away. I've had a few people PM me in the past with things like this, and wound up avoiding their work afterword.
-It could actually get you blocked from the site for spam.
-It makes you look desperate. The people who might check out your work in this case will likely subscribe out of pity and wind up being empty subs.
If you're looking to grow a real readership, there are a lot of other methods, but the ones that have worked for me (slowly but surely at least) were:
-Be active and engage in the forums. Share your work (not just comic links, but art in some of the threads here, participate in games etc) network, make friends. Connections make it easier to grow a following, and at the very least help with morale. Consider joining or making a discord server, even.
-Leave thoughtful comments on the work of others. (This sort of plays into the point above.) Be earnest, react, and tell them what you liked. Even if you can't comment on every episode it helps if they know you're there and engaged. Not only does this help with networking and building rapport with other creators, but it puts your name out there in the community. I've actually found several comics that I love through regular commenters on other comics I already liked.
-Engage with the people who have already subscribed with you. Thank them for reading, make posts on your page. Make sure they know how much they mean to you. (Please don't spam them though.)
Obviously if you want to start doing big numbers, you'll need to engage on social media, but I understand how time consuming that can be.
Just remember, building a community around your work is a long and slow process. Don't get discouraged, keep improving your craft with time, and keep pushing forward. As your work naturally improves and you get a longer reading backlog, it gets easier to attract new readers. Just make sure to keep going. This is a marathon, not a sprint.
Take care and best of luck!