ZigiMe, what an SEO developer does to increase really depends on the kind of site you’re running, and the traffic you’re trying to obtain. There
are also several different things that are looked at to optimize for the "whole picture."

Server/Hosting Factors:
You need to make sure that the web hosting package that your website resides on will work with you to obtain higher rankings. Some low-cost hosting packages do not really lend themselves to being optimized, there’s just too much clutter on them. Being stuck on a server with hundreds or thousands of other sites can cause:
-Your site to load slowly
-Your reverse IP address lookup to be very cluttered with results
-Your site’s shared IP address to be on e-mail/SPAM blacklists
-Have the server be misconfigured by your hosting company
-Cause security issues if you’re running an E-Commerce site

Domain Name Factors:
There are a number of factors about the site’s domain name itself that can help/hurt you including:
-How long has the domain been registered
-How long till the domain name expires
-How many other domain names to you own?
-How many links from other sites (backlinks) does your domain have?
-Do you have keywords in your domain/URL path?
-Do you have multiple domains pointed to the same site content?

On-Page/Site Factors:
By far, most of the work that can be done to optimize a site for better rankings is actually done on the site itself, with content and HTML code. There are way too many factors to look at to list in an article like this, and too many nuances to effectively learn SEO in a day/week/month. Some of the key things to look at:

-Make sure your site’s code is clean — If a search engine can’t come in and read the content of your site, it will be next to impossible to get your site ranked well (move JavaScript and inline CSS to external files for starters).

-Have your content in an indexable format (Yes SOME search engines can now read content within flash documents, but any professional SEO will tell you to keep your site’s main content and navigation out of flash/JavaScript)

-Keyword density — Search engines are first and foremost interested in good quality content. It’s what they were designed for. You want to make sure that every page in your site tackles at least one main idea, but no more than 2 or 3 main ideas. Search engines will look at a page, and based on keyword density analyze what the content is about. If you’re talking about a topic such as cars, you will naturally end up repeating the word a number of times. Search engines "know" what looks natural in text so if you have the word "cars" repeated too often on your site, they know you’re trying to cheat the system, and at best they’ll ignore the keyword, or at worst they’ll penalize you and de-list you from the index. Generally in SEO we use between 3% and 5% as a safe density.

-Cross linking — You want to make sure that your presenting; articles, products, categories, ideas, whatever your site is about, logically to the search engines. You want to control your site’s internal linking so you present your information to the search engines in an organized fashion.

Other Important Factors:
-Backlinks — Some SEOs will argue that backlinks are the single most important factor to getting your site ranked well in the search engines… This is true NOW to some extent. Search engines love to see references to your site from other people’s sites, because it means you have information that others like enough to sent their hard-earned traffic to. However, there are a number of ways that people can link to your site, that will give you zero benefit from the search engines. You also have to closely consider who these links are coming from (links from sites that are in no way related to yours count very little if at all). Search engines change their ranking algorithms sometimes a few times per week. If you rely heavily on backlinking to rank well… You’re really only one potential algorithm update from having your rankings slide from the first page to page 1,653,972 in a search engine.

The Bottom Line:
-Don’t put all your eggs in one basket. Don’t pick just one section of this information and just work on that. If you do, you’re only one algo update from shooting yourself, your site, and potentially your company in the foot.

-There are in some cases millions of factors that go into ranking a site in the search engines, and the above information doesn’t even begin to scratch the surface of all that an SEO does for you. Without seeing your particular site, and knowing your particular goals, I can only begin to talk in generalities.

-Having a truly well done SEO involves painting the whole picture correctly from the start. If you don’t have SEO in mind from before the first line of code is generated for your site, you’re already at a great disadvantage. SEO should not be an afterthought once your site is up, and you rea

I know what they do for the most part.

They pick a keyword phrase with little competition and optimize your site for that. It makes it easier to get on the front page if there is less competition.

Besides interspersing the website with that phrase (and other related keyword phrases), they use it for anchor text (the text you click on) for back links to your website on quality websites elsewhere on the net.

In short, an SEO person or agency:
1. Modifies your website so that search engines can easily access it
2. Modifies and adds content to your website to attract searchers
3. Builds links to your website to increase your search engine rankings

This is where I got my answer to that same question. After I learned what it entailed I figured I’d just let someone else do the dirty work for me.

http://sitefling.blogspot.com/

There are several good questions. I think what you are asking is ‘what can you expect if you hire an SEO.’ THAT answer varies.

Our SEO pros work through a Database that networks with 5 of the top search engines. We pay a subscription for this service. Our clients recieve a ‘crawler’ generated ‘grade’ for their page with a list of the things we need to fix. Then, they receive a second ones that show we HAVE done the work.

We also generate 12 reports that show indexed pages, keyword ranking, traffic, and what pages are in the top of the search engine results.

Finally, we use the clients data to figure out which keywords/traffic is drawing ‘buyers’ and which are just a waste of resources. We work to build a search engine marketing campaign to improve client’s sales (ROI).

NOW _ the thing is that there is no regulatory body. We are certified through SEMPO and the Internet Marketing Association. Most SEOs are self taught and do not upgrade their certification.

We have clients who say they get nothing but a hand written report at the end of the month telling the client how many hours they work – but nothing that they do.

Fact – SEO is not a one time thing unless you have an in-house marketing department. Make sure they want to do a monthly campaign.

Fact – No one can Guaratee you will be at the top of the search engines UNLESS they use keywords that no one optimizes for (because no one uses them to search)

Fact – There is a difference between sending TRAFFIC to a website and sending BUYERS.

Hope this helps