Instead of focusing on what to call the potential client, I think you can show your proficiency and maybe grab the client's attention by going through their job history feedbacks. It's a neat trick to be able to address them with their own name. I'm not saying it's going to guarantee you the job, but it will show that you are detail-oriented and you clearly know your way around the web.
Here's an example cover letter I did. I'm not saying this is perfect (no one is) but it does set you apart.
The three things I'd like you to see as takeaways from this are:
- Be creative, the first few words should get your client's attention.
- Be honest (and humble), show the client what you're bringing to the table and answer guide questions in your head like "Why should I hire you?"
- Be polite. You don't have to beg, in the end, it's all going to be up to the client to find the best fit for them but knowing you sold yourself as best as you can will give you the peace of mind to keep trying.
Hi Ronald,
You're probably wondering how I know your name, so let's clear that one out. No, I did not stalk you 
I read your job posting feedbacks from the past year because I wanted to let you know that I'm interested to work with you as a personal virtual assistant.
I've worked as an SEO consultant and customer relations specialist last year. During my tenure with my previous employer, I maintained relationship with my client's clients and did various administrative tasks on top of hiring and managing writers, conceptualizing blog articles, and securing various guest posting opportunities.
What I'm bringing to you as a possible virtual assistant is my great attention to detail and problem solving skills. My priority would be to help you do the things you need to do without constantly worrying about other time consuming tasks like scheduling social media posts through Hootsuite or Buffer, preparing text graphics with Canva and other similar platforms, and replying to your customers and clients through email, social media, and any other form.
To top it all off, I'm also very much eager to adapt with you as we go through all the other possible tasks you would need me to accomplish. I'm a quick learner and a very positive person.
All the best,
Vaughn Reyna
