To create buzz and momentum for your launch, run a presale offer of your product with some additional perks.
Jason Swett of CodeWithJason.com ($200/mo) did this for his previous venture, an e-book called Angular on Rails, and it helped him to eventually launch to 300 people with seven pre-orders. First, he wrote narrowly focused blog posts related to his product to increase relevant traffic. Then, he offered a lead magnet (a free copy in exchange for an email address) on that same topic to get subscribers. And, finally, he contacted those subscribers, inviting them to pre-order.