Site Structure for SEO
Content in Folders Structure
Folders divide categories within the root domain in Karl Kelman's personal web site. For example:
http://www.karlkelman.com/skipictures/a-basin
has Karl's Arapahoe Basin ski pages, and
http://www.karlkelman.com/skipictures/loveland
contains Karl's Loveland ski pages.
Other Site Structures
Subdomain Method (No New Domain Acquisition Necessary)
http://www.a-basin.karlkelman.com/
http://www.lovelandbasin.karlkelman.com/
Separate Domain Method (Requires Domain Acquistion)
http://www.karlkelman-arapahoe-basin.com/
http://www.karlkelman-loveland-basin.com/
Separate Domain or Subdomain structures are commonly inferior, from an SEO perspective.
Personal websites generally lack significant Page Authority (inbound links and related factors). Official larger business website sites (skiloveland.com, etc.) have greater Page Authority, relevant domain names and long domain age; national sites and media articles about ski areas have even greater page authority. Karl's pages must concentrate authority into a single domain to be competitive, even for long tail search terms ("Loveland Basin Avalanche Bowl").
Some minor reasons that a single domain is better:
1.) Domain age is generally better for a single, more general domain. For example, karlkelman.com was founded with no particular view to become a large site with several hundred pages and multiple categories. Like most sites, it evolved into a larger site. Obtaining a separate domain ("loveland-basin-skiing.net" or similar) for a category that evolves years after the original site would mean less domain age.
2.) Less expense and upkeep. A single domain is one domain renewal, one hosting account, and can often share many CSS (Cascading Style Sheet) and Javascript features from page to page.
Important Exception to the General Rule
If you currently dominate search results for your entire line of products and product type (think Hewlett-Packard with printers - they are a good example of a company that's improved their web presence with subdomains), separate and subdomains may enable you to expand your domination of search listings - in addition to the top two spots in search results (search engines generally only give two listings to one domain), you may be able to be #3 and #4 as well.
This is a strategy that only works if you have overwhelming online dominance with respect to your industry and market area. If you have 100 units of Page Authority, and no competitor has more than 3 units, your Page Authority can be divided among several pages, and each of those pages may still outrank competitors.