How much would a website similar to twitter cost to construct and maintain?

[Locoluis]

The basic ideas to twitter are rather simple to implement, in theory.

Essentially, you need:
- A table of users
- A table of relationships between users
- A table of messages
- Some other data.
- LOTS OF INDEXES to improve your searches, including:
-- Hash tags
-- @user mentions
-- URLs (and tinyURLs)
-- Images
-- etc.

You need to be able to serve that data to desktop computer and mobile users.

However, what's really cool of Twitter is the way they handle the COLOSSAL traffic they get. You need LOTS of bandwidth and computer resources to achieve their results. You have millions of clients checking out every single second for new tweets. You need to provide that information in pretty much real time.

Wall Street Journal says that Twitter nowadays (February 2011) costs around $10 BILLION dollars. There are no available figures on the Total Development Cost of Twitter, though; I bet it must be a significant fraction of that.

You don't want to learn how to program, design databases, design high-demand web services, design a security model, etc., so the only way you can realize that great idea you seem to have is through lots of money from your pockets.

I just hope you're not yet another dotcom boomer.