My response to your question is, it really depends on the services being provided. I worked in telecom for 14 years selling technology and voice and data networks. That sales cycle was much different in many ways compared to what I'm currently doing in my business. As a photographer, I often call on national meeting planners who will be bringing a conference to my city. All of that initial correspondence is through email. I send introductory letters and proposals based on the conference dates and requirements. I'll follow up with an email because it less threatening these days. Often, I'll get a response as well as no response. I've become less emotionally attached to the proposal and the potential client response or lack there of.  I'm also at a point in my business development where I'm not feeling as desperate to get every piece of business because I come to know that not all business is good business, particularly psychologically. So, with that in mind, keep it simple and institute a strategy that you're going to do with the highest degree of consistency. That way we only have one personality and one mindset to manage and that's our own.