First and foremost I liked the look of it. I'd seen this game demonstrated at various shows and it looked spectacular. I know that a similar effect could be achieved with a different rule set but the fact is that Battlefront (the makers of FoW) have put a lot of effort into the design of the game. It could be argued that I'm a sucker for good marketing, but I also think that in this case it reassured me that this was a game system that was a) going to be around for a while and b) would be well supported. The latter is definitely the case and the FoW website not only promotes their products but also provides a wealth of other material - histories, briefings, new rules etc - for free. And I like free.
The other factor that influenced me was the scale. I've wargamed with 28mm before but nowadays I just don't have the space to store boxes and boxes of models and scenery. 15mm is significantly easier to store and transport while still maintaining a challenge to my painting skills. I felt that anything smaller just wouldn't be as much fun to paint. I now have a growing selection of vehicles and troops that fit neatly into a single carry case and all my scenery fits into one large storage box. This is a far cry from the days when I played Warhammer and needed three cases just for my figures and several boxes for accessories.
Another factor was the way that Battlefront sell their miniatures. By supplying boxes that include whole platoons and companies, you don’t have to find all the bits yourself. For example I recently bought a Panzer Grenadier platoon that has all the models for five half tracks and 15 squads of troopers plus a command stand. I think this 'modular' approach makes it much easier for new players to adopt the rules system. Now that I have done more research I feel more confident in buying tanks and infantry platoons from other manufacturers such as Peter Pig.
This brings me to one of the other main deciding factors. I'm a bit of a Treadhead and I have a particular interest in the German Panzer Divisions of the Second World War. The first time I saw this game being played it featured a brilliantly painted Panzer company and I thought to myself "I want one of those"! For me the models are important and those that I saw were excellent quality castings. My painting hand was twitching when I saw those models.
One final point. I've never really been a connoisseur of rules systems. You won't find me discussing the relative merits of System A over System B on the web forums. So when I was deciding whether to throw my lot in with the Flames of War camp I went out and asked players what they thought of the game. I read reviews and feedback on various forums but most importantly I spoke face to face with actual players to find out what they liked about their chosen system. Everyone I spoke with was friendly and helpful but what came across most about the FoW players was their enthusiasm for the game and willingness to help a newbie grasp the basics.
I'm sure there are plenty of hard core wargames out there who would love to tell me why 15mm isn't the best scale to play; why WWII isn't as interesting as Napoleonic's; why FoW isn't as good as PBI or Rapid Fire; and why Battlefront are the spawn of the devil, only equaled in 'Selling out to The Man' by Games Workshop. FoW might not be to every wargamers taste but the quality and variety of the models, Battlefronts product support and the enthusiasm of existing players made this an easy choice for me.