The marketing budget is the most I'm willing to spend to get going while there still aren't any customers. This is all coming out of my pocket, including design

The marketing budget is the most I'm willing to spend to get going while there still aren't any customers. This is all coming out of my pocket, including design, development, hosting, and other costs for some of the premium features. I'm clear on my audience (HR leads at medium- to large-sized businesses looking to reduce costs and increase efficiency for this part of their job responsibilities. I'm already casually doing what you suggest with Adwords research using the adwords targeting explorer. The other advice about forming partnerships or a CPA program (what is that, btw?) is intriguing. Thanks!