The uses you could make of a product category domain name.

Once you acquire a quality product category keyword domain name, what are you going to do with it?  That is, how will you deploy it in order to reap good returns on your purchase?  The following options are listed in a least-to-most order:  least effort to greatest effort, but also, least returns to greatest returns.

1. At the very least, locking competitors out of the use of this domain.  You accomplish this simply through ownership of the domain — if you have it, they don't. In many cases, this by itself could be worth the entire cost of the domain name, with no further investment. 
     
2. A redirect to your primary site.  This won't help much in the search engines, but at least, if someone types the domain name directly in their browser — and many do — this will lead them to your site.  It's better than nothing, and takes only minutes to set up:  a worthwhile first step until you have time to deploy it more effectively.
      
3. A "doorway" site or doorway pages for your product category — perhaps specifically for a country in the case of a country code domain name — optimized for specific keywords related to your product category, and linking to your primary site.
     
4. A site featuring your own products in the category.
     
5. A site about your product category, either overtly branded with your company logo or more subtly carrying ads for your products and primary site.
     
6. A more general site about the category.  Here the possibilities become too complex to list in a meaningful sequence — it all depends on the implementation.  You could have a PR and information site advancing the product category, perhaps with advertising for your own products.  The site could even be a portal for wholesalers, distributors, dealers, resellers, affiliates, franchises and/or rental outlets, as well as newsletters, blogs and other social networking media.. 

Any of these options would be helpful, and it makes sense to start immediately with something simple like a redirect, and then move up to doorway pages or a doorway site.  To harvest the full potential benefit of the domain, however, sooner or later you'll want to develop the site more fully.  Otherwise, http://www.domainsherpa.com/pg-is-wasting-half-a-million-dollars-a-year-on-toothpaste-com/" target="_blank">as this shocking example makes clear, you'll be leaving money on the table.

Finally, if you regard the domain as an asset acquisition, it's always an option to sell it later.  This is just like buying land and holding it to develop or sell later.  In fact, from the investment standpoint alone, this may be one of the best places to put your company's money.  One expert says:

Recognize that good keyword generic domains are an appreciating asset.  Regardless of whether your company tanks, your .com domains will continue to go up in value, if you have purchased well.  They will appreciate faster than stocks, real estate, funds, offshore investments, IPOs, art, antiques, gold, jewelry, collectibles, sports cards, or classic cars.

The same is true in countries around the globe — only more so, since in many places the online market is still growing rapidly.  As the market grows, so does the value of the domain.  The same site, by the way, urges the purchase of "category" domains like those we have been discussing.  

The uses a competitor could make of a domain if they had it instead.

The uses a competitor could make of a domain are the same as the uses you could make of it — only in this case, these uses would work against you instead of for you.  If the domain you are considering was in the hands of your fiercest, most aggressive competitor, how much business could they take away from you, or keep you from getting in the first place?  

Remember, new customer "eyeballs" and clicks are the first step in the conversion process that leads to new business.  With a good product category keyword domain name, well deployed, a competitor can siphon off that new business to themselves and away from you.