Customers, not followers, are what makes a business. People are very accustomed to pre-orders these days. As long as you are transparent with them so they have the proper expectations (e.g., you will receive your product in December), then get the pre-orders. You can likely use the pre-orders to increase your followers at the same time.

There is nothing wrong with getting followers, but you need to have a sales and marketing funnel that converts them into buyers. A good product launch plan, as suggested before, should include such a funnel. However, followers for the sake of followers is self-deception.