What I Hear as an Agent Linda S. Glaz

Okay, people ask me this question all the time. 

     Why do I need platform before a book is contracted and how do I grow it without a published book?
     Publishers want to know "ahead" of time that you are working hard at connecting with potential readers. That you can market! That you're willing to put in the work.
     So how do you do it without a book?
     Let's look at an historic author pre-publication. Create a website/blog that engages followers with items about your time period. Era recipes, era clothes, one-page short stories, interviews with other authors who write historic. Most are eager to be posted on someone's blog to promote their current release. 
     Once you've set up your site, about 20-30 minutes a week will keep it up to date. BE consistent. Post short articles or reviews on your FB page. There is PLENTY that you can do to get followers who will turn into readers once you have that book. Can you do reads in your genre at the library? Speak at ladies' teas (men's breakfasts) at churches on what a writer's life is like and how to maintain the faith while writing/waiting. There are numerous ways to build that following, and more and more, publishers want to see plenty of marketing work coming from you BEFORE they give you a contract!      
     Look at it this way: if two amazing books are offered to them, and they LOVE them both, but one author has a total following in all his/her social media of about 963, while the other has a total of around 11,674, who do you suppose they will lean toward? 
     You can do this. But you have to make the start and follow through! To say, "I'm a writer, that's not my job," shows that you do not understand the industry. 
     Yes, marketing IS part of your job.