I'm putting together a business case for the developers in my company to get a second monitor. After my own experiences and research, this seems a no-brainer to me in terms of increasing productivity and morale/happiness. One question which has niggled me is if I should be pushing to get all developers onto a second monitor or let folk opt-in (i.e. they get one if they want one). Thoughts on this are welcome, but my specific question relates to a snippet on this site:

But when the IT manager at Thibeault's company asked other employees if they
wanted dual monitors last year, few jumped at the offer. 

Blinded by my own pre-judgement, this surprised me. Has anyone else experienced this?

I fully appreciate that some people prefer a single larger monitor, but my general experience of researching the web suggests that most programmers prefer a dual (or more) setup. I'm guessing this should be tempered with the thought that those developers who contribute to such discussions might not be considered your average developer who might not care one way or the other.

Anyway, if you have experienced the above have you tried to sell the concept of dual monitors to the masses? If everyone just got 2 monitors regardless if they wanted it or not, were there adverse reactions or negative effects?

UPDATE: The developers are on a mixture of 17", 22", or 24" single monitors. The desks should be able to accommodate dual 22" monitors as I am proposing, though this will take some getting used to I imagine.