Search Engine Optimization
It is recommended to use schema.org to tell search engines how your news article are structured.
NewsArticle
On http://schema.org/NewsArticle you can see what information you can provide to search engines.
A new section within the NewsArticle schema allows you to specify if you are using a paywall or not. If you add the following example to your schema it will be compatible with the SmartWall.
"hasPart":
{
"@type": "WebPageElement",
"isAccessibleForFree": "False",
"cssSelector": ".sw-paywall"
}
It is really important to avoid what google call "cloaking practice". You can find more information about it here: https://developers.google.com/search/docs/data-types/paywalled-content