Brand Domain
You will found interesting is, a lot of well known and successful websites do not use keyword as their domain name. These online businesses have chosen to go with a completely original domain, and brand it. A few success examples like Google, Yahoo!, Amazon, Monster, and eBay. These companies are successful because of their company brand was consistent and not because keywords got them to the top. Consumer recognize their brand, because of the quality of service or product they provided. They feel justified, and likely to buy from them. However, to build a brand take serious work and large amount of resource. You need time to build it.

Keyword Domain
A keyword domain is a domain chosen to take advantage of search engine traffic. By choosing a domain that matches a keyword search, we are able to rank higher for targeted keywords and thereby benefit from added traffic and more potential for sales. For example if you are selling toy from China then you may choose something like "chinatoy.com". The companies who are success in using keyword as their domain name like Search.com and Job.com. From these two success examples, you can found that they are using single word as their keyword. But it seem difficult to get single keyword domain, that is short and relevant to your industry obviously that would be better, and I doubt you'll ever to get one unless you are ready to shell out thousands or perhaps millions just for the domain name.

So, which one should you go for? a brand based domain or keyword domain? For me, your decision is much depending on your business plan. If you web business will be used once by the visitor, and then most likely never used again, then keyword domain seem more logical. But if the return visit is very important for your business, then a brand based domain sound more helpful.

Furthermore, If you have a large offline advertising budget and the budget necessary to brand your company, then I will recommend you should go for brandable domain. If, on the other hand, you have a limited budget, I prefer you choose a keyword domain and let the search engines bring the customers to you.