Choosing the right category

Hi,

I guess this is more of a general issue, but out of the available categories product, item review, article, service within the plugin, how are we supposed to make the right choice for put posts/pages?

I noticed that the pages where I set “product” will more likely show the stars in Google SERP, which is amazing in terms of stand-out effect.

But I’m not quite sure if it was due to the category “product”, and maybe the fact that I had a few clicks on the stars from some users around (in fact, “product” is the only one that allows other users to rate).

Could it be otherwise due to just the importance of that specific page, or maybe other mixed reasons?

Product, item review, article, service are all often logically proper to a page/post but I wonder which one is more effective in terms of chances of getting a good rich snippet in the SERPs.

Thanks a lot!