What specific information system does twitter use?

[Sam]

Does anyone know how it collects information?
I'm thinking one way must be through hashtags.. But I can't think of anything else. Any input would be appreciated!
Hi!

I'm mostly just wondering about personal information such as name, email and other contact information. How do they use this information? Do they target ads, or sell the information etc.

[Open Sauce]

Could you expand the question a bit, not sure what you mean by 'collect information'.
Edit: Ok I understand now.....anytime someone goes to a web site the webmaster can determine certain information about the user such as what operating system they're using, what browser they're using, what site they were on before going to their site, and where they went when they left, together with ip address, country etc. Couple that info with cookies and you can determine a lot about your users. Try this little experiment go to google and search for something, say for example 'web hosting'. Browse a few of the sites that come up in the search results then carry on using the internet how you normally do. You will find that on many of the sites you normally visit, you now have adverts relating to web hosting.
Compare that with 1000's of people at home watching TV when the ads come on, they all see car ads, shampoo ads etc, but they all see the same ads. On the internet, everyone sees different ads relating to their searches, all this info is gained via analytics and cookies.