I do a full page once a year in December for the January Newspaper.... the entire page is composed of our sales.... photos of listings.... and a thank you to all who did business with us....

Fortunately, my company's website allows the agent to list their past sales on their personal profile which is under the company banner. HowardHanna.com

In my training classes, I discuss the benefits of listing past sales.

It was NOT important to me as I had a very set clientele. If I took on a new client I'd just review with them my track record. I always had as much business as I could comfortably handle Joan Cox 

I think your past sales speak volumes for your ability to produced results.  You can add them manually to Realtor and Zillow.  I've done that quite a few times when things don't sync properly or when they were done off market.

Most of my sales are on Zillow. They are all on one of my websites. I don't worry about Realtor.com.... don't see any real traffic there.

A little confused about your question since you ask about Realtor.com and mention your website. You should be able to set up something on your website.

By the same token, I've never had a prospective client ask to see a comprehensive list of my sales.

Never an issue for me. I was involved in new construction onsite sales and management the last 10 years of my career.

On our new site there is a section where we can do that so I did & I like it.

Ordinarily I've never had a seller ask other than you sell in our area right?

I really don't care what Z does & every time I go in there, it's not correct.

For those who use online sites for reviews, I suppose it's important. Our MLS syndicates and I often receive reminders to confirm a sale. So, it's pretty automatic for us here.

The more you can show sales and testimonials, the better in this age of people researching you before working with you.

 Joan,

It depends on your strategy and your overall marketing plan.  A

I dont know how many people pay attention to that.

Our company website does it

Barbara has a great idea to set yourself apart from other realtors.

It is important for clients to know we do business.  You can input them into Z.  Run a blog on your website and share it to other sites as well.

I do not list my sales on my website for many reasons.  I do have testimonials on my websites. 

I work a lot off book because I don't want other agents knowing what I am doing.

Not part of my sales strategy, never has been. According to Z, I have had ZERO transactions during my entire career...LOL

I do syndicate my sold properties.  

This was never an issue for me.

I don't even have a profile on zillow.  So not at all.  My wife claims all of hers.

I believe some sites do it to have more SEO. I do advertise my past closings.

Unfortunately, it is very important. 
How do I know?  Well you can be sure I don't ask the experts, I ask the citizen. The citizen has NO INTEREST in real estate agent Success Theater.

But, why it is important is not what you think.

It is all about how we promote ourselves.

Not a problem. Our Team has done over 100 sides for the each of the last two years. We show up in plenty of places.