When SEOs talk about Web 2.0s which tactics are implied with that?

I often see something like "stick to web 20s"
But what exactly does that mean.

I hope you can help me clarify this.

Web 2.0's are sites like domain.wordpress.com, domain.blogspot.com, domain.myspace.com etc, as opposed to domain.com. Saying 'stick to', implies that you should use them instead of the full domains.

you don't have full control over web 2.0. so its good for testing and tier 1 but don't use it for your money pages.

WEB 2.0 is a term that usually means a website that allows you to interact with others.

Usually this means Social media sites, and blogs. For the purposes of SEO it actually means anywhere you can set up a web presence on someone else's platform, that allows you to tap into the popularity, (and domain authority) of that platform to increase your own authority and ranking.

Since Google doesn't like you to promote your own sites, you cannot set up a auto pin stripping site and connect it to your auto pin stripping business to get link juice. Google knows that you did it, so it doesn't count.

But if someone just happened to put up a car pin stripping blog on WordPress, or Blogger, or even Weebly, and found your site and liked your site so much that they had to link to it, why Google likes that very much.

Some direct promotion is allowed, Facebook, linkedin, twitter are web 2.0 properties that you can gleefully link to your site, Google has no problem with it because this is an accepted way to promote your business.

Since these properties are huge there are a ton of links coming in each day, so you can also build links to your own page and just be part of the crowd.

Unlike your money site, if you overdo the linking and get a penalty to a web 2.0, you simply delete the page and it all goes away because the web 2.0 no longer links to your money site.

for money site you must get paid domain