Why are there so many product reviews recently

In case you're interested in knowing why there are so many product reviews being posted recently (near the end of March, 2019), here is the story.

I used to be pretty consistent about emailing people to ask for reviews of products bought from my online store. Then, about a year ago, Google notified me about their new review system, where people can review my products and stars will show up next to my products in google searches. I began reading about how to do that but the thing that I could not get past was that the hundreds of reviews I already have cannot be transferred to google. And, if I wanted reviews to appear as they are now in my store in addition to google, people would have to review their purchases twice. That would be an unacceptable burden to place on them. So, I had to decide whether I wanted to use google reviews or to continue with the system that is currently in my store. I procrastinated with this decision.

But, I've finally decided to keep the system in my store and forego google reviews.

So, I've send out a few hundred requests for reviews today and they will all be entered in the system in the next few days. Even though they are for sales from the past year or so, the reviews are all dated recently. Hope that explains it.