What are wildcard domains?

[Marcia]

I've been trying to find out for a while, can't seem to find any info. I've no idea what they are.

[Ove]

Hi Marcia

[webmasterworld.com...]

/Ove

[Brett_Tabke]

Wildcard DNS allows you to use "anything" for a third level domain. They are called wildcard to refer to the fact you can use any keyword in the 3rd level domain.

*.domain.com
marcia.domain.com
bob.domain.com

On the tech end, you should know that the 3rd level portion of any domain is handled by that sites DNS server. If the dns server is configured to allow wildcard dns, then any word can go in the 3rd level spot.

They are a serious issue for search engines because of the level of spam that can flow from them. If you run a site on widgets, you could do:

blue.widgets.com, red.widgets.com ...all colors to infinity

What some sites did was custom generate pages out of those 3rd level "keywords" as database miners.

An equivlant would be the site search engine. Instead of the long url to do any search, we could toss around marcia.searchengineworld.com and then on the site end, we'd look up marcia in the search engine and produce the results page.

That type of setup was used to spam the tar out of some engines like Ink a couple years ago. Millions upon millions of 3rd level domain keywords were stuffed into the engines. It left a very sour taste in their mouth and a distrust of 3rd level domains.

[Ove]

Brett would you recomend to use wildcard i have thought about that but i think subdirectory will be safer.

Will SE give bigger boost for subdomains?

/Ove

[Brett_Tabke]

Your mileage may vary. Some people are using them with success. I like subdirectories best.