Facebook has had a $500m offer for social networking site Twitter rejected.
The offer was not a straight cash deal but in stock form with Facebook's valuation at $15bn which came from the Microsoft investment in October. A more accurate valuation of Facebook is around the $5bn mark making the true value of the offer $150m.
Twitter is two years old and does not make any revenue at the moment despite looking at adding advertising and charging business customers next year. So far Twitter has not found a revenue stream to rely on and depends on private investors.
Twitter's investors were looking for a monetary deal or stock at what they felt was the true value of Facebook as opposed to the overvaluation proposed.
It seems one of the main reasons to reject the offer was that Twitter's investors believe it has opportunities to grow and that accepting the first offer on the table would restrict its potential.
So what is Twitter?