You can split a long WordPress post into multiple pages for reduced per page images load, easier for the readers to browse through the article and every page click to the next page will increase your page views.
WordPress provides some inbuilt functions which can be easily used to divide any new or existing WordPress post into multiple sub pages. On most well-coded themes, all you have to do is paste the following Tag where you want your content to be shown in next page. The pagination will automatically show up.
<!--nextpage--> // You need to use the html-mode of the editor to do so
If for some reason, pagination is not showing up after you have pasted the next page tag, then you would need to add the following code in your theme’s single.php loop.