Narrow site focus or start narrow & build wide?

I posted this in another forum but didn't have the response i had hoped for:
I'm a little behind in performing the assignments due to life happening. At this point I'm still working on my niches and an overall strategy. That's my question - single product niche sites or a niche with multiple products. Let me explain.
Jeremy has shown us several examples of single product sites - like ultramobleguide.com. I understand the marketining, design and significance of a single product site. However, Jeremy keeps stressing that our overall goal should be sites that are designed to last. In that light, let's say I want to do computer equipment for home office users - backups, monitors, PCs, audio, printers, etc. I might even narrow the focus to home office users who are sales professionals or photographers for example.
Questions:
1. Is it better to choose to set up a site for each product category - pcbakcup.com, monitors.com, etc. Or would it be better to select a site domain like homeofficetech.com? If I chose homeofficetech.com, I could start with one product category, build it, market it and develop sales from it. Once sales were coming in, I could then add another product category to the same site. Obviously there would be a home page with competing products but I could still have landing pages for product categories (i.e., PC backups) and for specific recommended products (i.e., low cost backup devices). By doing it this way you would have a site with more content and that might add more value to users.
2. Is the single product niche site really designed for long-term? Jeremy's site may perform well for a while, but what happens when ultramobiles aren't hot? Or they become commonplace? Wouldn't it be better to design sites around a target market rather than a product category?
I'd be interested in Jeremy's thoughts on this as well as everyone else's input.
Thanks!

1. Is it better to choose to
1. Is it better to choose to set up a site for each product category - pcbakcup.com, monitors.com, etc. Or would it be better to select a site domain like homeofficetech.com?
I would start with a smaller niche (e.g. pcbackup.com). Once you've mastered a few of these smaller niches you can be more ambitious.
Starting with a more specific domain will help you become an authority. If cost is an issue, you can consider doing sub domains on your primary domain, but at $10/each domains are a pretty small investment with the potential for a great return.
2. Is the single product niche site really designed for long-term? Jeremy's site may perform well for a while, but what happens when ultramobiles aren't hot? Or they become commonplace? Wouldn't it be better to design sites around a target market rather than a product category?
You're assumptions about the market are correct - find the market, then build a site around it. You'll note that my domain is "ultramobileguide.com". This doesn't tie me down to a specific product. The need to go mobile and to save money on notebooks isn't going away any time soon.
Registering a specific product domain - a la EasyMediaCreator9.com or EasyMediaCreator10.com works well for paid search and other short term opportunities, but isn't necessarily a good long term strategy.
Keep in mind that a large part of business success is riding trends. Sure online dating isn't as big today as it was two years ago, but I sure made a hell of a lot of money while the getting was good. I don't make as much money today in that particular niche as I did two years ago, but I didn't curl up and cry about it ;) I found a few more rising trends and completely replaced that income.
You're going to have to make adjustments, no matter what you do. Affiliates adapt or they go out of business.
OK. Good points. Thanks for
OK. Good points. Thanks for the feedback! U da main!
chopper
Just the answer I needed
I've been struggling with the same question (and, funnily enough, had settled in on the same general "home office" niche though from a very different angle).
[sigh] back to the drawing board to decide on a deeper topic. I have an older microsite dedicated to webinars, for promoting Webex, that doesn't get much traffic. Maybe I'll take what I"m learning here and apply it to that site.