Is it worth to use meta keywords
 

Is it worth to use meta keywords tags anymore those days ? Ex one of my posts Free Porn chat

I do use them in my sites but i suspect they are good in anything

Yes, its def worth it.

For google you don't need meta keywords,google now working in some different way

Google has stated that their algo disregards the meta keywords. Personally i don't use them because i suspect that using meta keywords is letting google know exactly what you are targeting, not best practice.

If anyone has experience of pages that work with meta KWs and think that it's because of that, i'd be happy to hear about it.

i just diversify, in some of my sites i use meta keywords, in some not.....also depending on the site character ..... and works perfect. I think google likes diversity:thumbsup

it doesnt hurt to use it

I never use them these days...
1. Major search engines ignore them (and possibly might use them to check if you're spamming, who knows)
2. Easy for competitors to see what keywords you're targeting

Even if it does nothing whatsoever, is there any harm in using it anyways just in case?

You should use different and unique title and description ( meta keywords ) for each pages according to google new updates

Meta tags won't hurt you in the search engine rankings, just make sure you use them to accurately describe your site (the purpose for which they were originally intended). The major search engines quit using them for indexing purposes years ago due to spamming, but certain tags are still used to supplement other data on your site. For example: language, viewport, title, description etc.

In addition, social networking sites will often use meta tag data from your site...Facebook's Open Graph is a great example of why you should still use meta tags:

http://davidwalsh.name/facebook-meta-tags

FWIW, I have always used them and still do.