1. There is no need for Antivirus / spyware / Anti adware
2. No piracy
3. System would be fast and zero maintenance.
4. It has all the required softwares

Most of the people I have converted is elderly who are using old computers with 1.2 Ghz pro / 256 memory .. like that and they are very happy and no problems at all. But I have converted one of my best freind who is a basic user and bought a new laptop with Vista basic. I gave him my reasoning and installed it in his laptop and he is more then happy with it. Not even booting to Vista once in the last two months.

A user of XP will know about malware, crashes/BSODS/popups and will know that Vista sucks.

Suggesting to a user/potential user of PCs that he/she might be interested in a system that does not use XP or Vista and has none of those problems will work whether the motivation is for new hardware, speed, reliability or lower costs.

The hottest market today is the netbook. They are cute, easy to carry, boot quickly, and about half of them run GNU/Linux and work out of the box. The product is attractive, particularly to kids and women because it is a better size/price and they do not need to know anything about GNU/Linux or that other OS to use it. These and thin clients are the wave of the future and they work better with GNU/Linux than with that other OS. Little selling is needed. Show it to them and you have a winner.

“* Ubuntu is a free, easy to use operating system I think you should try [OK. Why should I?]. It is based on some generic code called Linux that forms the base system.[Huh? Code? Great reason... I don't care about code.]”

Furthermore, not a lot of people heard about Linux – and most of those that did, heard pretty bad things. I’d say it’s easier to introduce Ubuntu first and then point out that it’s a Linux-based OS.