Question : Multiple domains and SEO

We are contemplating "satellite" sites of our main website which would be geographically focused. Each site would be essentially a different access into one underlying site. We would like the links from the geographically-focused sites to improve the SEO ranking of our main site due to the back links. However, we are wondering if this in fact is possible.

Here are example of the three approaches that we are considering for creating these sites:

Subdirectory:     www.Example.com/Maryland
Sub-domain:      Maryland.Example.com
Domain:            www.Example-Maryland.com

It seems to me that the "domain" approach would have a better chance of enabling SEO improvements.

Does it make any difference? What are the pros and cons, given that the amount of work needed for each approach is quite a bit different?

Answer : Multiple domains and SEO

All three methods will be able to rank well (and on top) as long as you follow the SEO rules (content & links/credibility). There is not one true method guaranteed to be higher than the other methods. Page rank is ultimately decided by how many relevent keywords / content / links that you have within your sites.

Subdirectory:     www.Example.com/Maryland (Safe SEO method, fast page rank results)
Sub-domain:      Maryland.Example.com  (consider Google changing its SEO rules, you may want to play safe by skipping this one for long term goal)
Domain:            www.Example-Maryland.com  (Unnecessary)

I would suggest using "Sub- Directory" method. This is the most safe and friendly way to approach SEO.
You really wouldn't have to worry about Google changing it's SEO  "rules".