I highly recommend ‘Hacking Growth‘ by Sean Ellis and Morgan Brown.
Sean grew LogMeIn and Dropbox from startups to massive tech giants and coined the term growth hacking. This book is unique because it gives you a step-by-step growth process to follow, plus proven tactics that you can apply to your business today.
This is hands down the most relevant marketing book of 2018.
About: Kristen Proctor is the Founder and CEO of Rocket Strategy, a growth strategy consulting partner to innovative tech startups and Fortune 500s. Kristen has several years of experience leading growth at successfully scaled tech startups and public corporations. She is also a contributing writer for GrowthHackers.com, Inbound.com, Fast Company, and Inc.