Ask HN: Buy multiple vertical domains or focus on one main domain?

[trendspotter]

I just discovered that a large pool of .com domains for multiple markets where I could offer a product, is still available and not taken. These domains are similar to this:

[Vertical]Mytopkeyword.com BusinessMytopkeyword.com MediaMytopkeyword.com ScienceMytopkeyword.com TravelMytopkeyword.com SportsMytopkeyword.com RetailMytopkeyword.com MarketingMytopkeyword.com AutomotiveMytopkeyword.com ManagementMytopkeyword.com

Almost any domain and market with my top keyword is still available. I could basically grab them all in one minute. Should I go ahead and buy like 20-30 domains to cover all these areas direcly, or would it be for SEO a better move to use all these market keyword all together on a single domain instead (as a subdomain) like for example:

[Vertical].Mybrand.com or Retail.Mybrand.com or Travel.Mybrand.com ?

[philiphodgen]

1. Domain names are cheap. Grab them.

2. You understand subdomains. Most people don't. Don't confuse your customers.

[trendspotter]

Thanks for pointing out argument number two.