When it comes to search engine optimization, there are a lot of myths and rumors floating around about what does and does not work. A lot of this "knowledge" appears valid, because it sounds like it should be true, but beware!
Much of the information floating around about the right way to optimize for the search engines (especially Google) is very, very wrong. A lot of it is based on assumptions: "Google must be smart enough to consider [erroneous conclusion here]..." or "I BELIEVE Google [additional erroneous information here] ..."
Some of it is based on old truths. For example, search engines used to have a harder time indexing script-based sites (i.e. PHP instead of plain HTML), and so those sites didn't do as well in the index. But that was a long, long time ago (in web years anyway). The engines have long since been ranking script-based sites in among plain HTML with no problems -- but the rumor is still heard even today.
Be careful what you believe about SEO. If you're reading an article or forum post about a particular method or technique, make sure it's backed up with actual data, evidence, and examples before running out and starting to apply it to your site. What you'll find in most cases is that the supposed "facts" aren't actually being demonstrated or backed up with proof and examples.
Let me give you two BIG myths as examples, and show you actual proof that they are, in fact, bogus (at least right now).
1. The Themed-Link Myth
This is one of my favorite myths. Everyone assumes that Google simply must be smart enough to know whether your links are coming from sites that have the same (or related) theme, and therefore links from sites with the same theme are the only way to rank for your keywords.
Google may, in fact, know whether or not the links are coming from websites of a similar theme. It may, in fact, add more weight to these links. But to claim that you must get links from similarly-themed sites in order to rank is pure mythology. Here are some examples that disprove the claim:
Keywords: search engine optimization
Rank: #3 in Google
The phrase "search engine optimization" is probably one of the most difficult phrases to rank for. After all, all of the best search engine marketers want to hold the top positions for those keywords in order to sell their services. Submitexpress.com is doing very well in this regard, ranking #3 for the phrase (as of this writing). Number one is held by Wikipedia, and number two by Google itself.
If you go to Google and take a look at the backlinks pointing to submitexpress.com (using the link: command), you'll notice that very, very few of those links have anything to do with search engine optimization or marketing at all. The exception are links shown from the domain itself, and that's almost it. So if it's such a fact that you have to have links from similarly-themed sites in order to rank for your keywords, how does this site manage to pull off such a huge feat?
Simple: you don't have to have links from sites of the same theme -- you just need a lot of links with your keywords in them!
Keywords: free cell phone
Rank: #1 in Google
Yes, this site ranks #1 in Google for the very competitive phrase "free cell phone". But almost none of its backlinks come from sites or pages having anything to do with cell phones, or phones, or communications in general (go to Google and see for yourself--but be warned, some of the links are from adult sites).
So again, another site ranking for a competitive set of keywords that somehow manages to do it without "themed links". How is this possible if you can only rank well with themed links?
And again, it's simple: you don't have to have links from sites of the same theme -- you just need a lot of links with your keywords in them!
Here are a couple more examples that rank very well for difficult keywords despite almost all of their links coming from off-theme sites, in case you want to explore further (but I won't go into detail about these):
Rank: #3 in Google
Keywords: affiliate programs
Rank: #1 in Google
Does this mean that Google won't put more emphasis on theme-related links in the future? No, it doesn't. They might, they might not. But whether they aren't quite as "smart" as people think they are, or they've just chosen not to do it (for whatever reason), it is still quite possible to rank for very difficult keywords with all of your links coming from off-theme sites.
One point that has proven to make a real difference: Google is discounting reciprocal links more than it used to. They still matter, just not nearly as much. One-way links appear to be the way to go.
2. The Themed-Content Myth
Another "common sense" notion about Google is that all of the content on your site should revolve around the same theme, otherwise it won't rank well for the keywords you want to because your theme will get "too diluted".
The number one biggest proof against this notion is Wikipedia.org. Wikipedia.org covers almost 2 million very diverse topics (as of this writing), and yet ranks incredibly well for a huge array of keywords. In fact, there are few informational searches you can do on Google these days that Wikipedia doesn't rank well for.
As one example, take "internet marketing", for which Wikipedia ranks #1 in Google. There are a few related pages around the subject (about 426 as of now), but Google has 3,220,000 pages indexed for Wikipedia -- of which the vast majority have nothing to do with internet marketing.
How is this possible if everything on the site has to be theme-related in order to rank well for the keywords?
Simple: the notion that all content on a site must be of the same theme is a myth.
But Wikipedia is seen as a kind of deity among websites. Are there any "lesser" examples? Yes. Here are a few of them:
Keywords: energy drinks
Rank: #2 in Google
The "energy" subfolder of bandddesigns.com has a few hundred pages devoted to energy drinks, for sure, but if you do a site:bandddesigns.com command at Google, you'll see that the site has 4,320 pages indexed on a very diverse set of subject matter that has nothing to do with energy drinks (or health in general). Despite this, it ranks #2 in Google (just under Wikipedia, which again, is not all about energy drinks).
So do you have to have 100% related content on a site? The facts say no.
Well, then, how is this site ranking for "energy drinks"? Check its backlinks (especially at Yahoo) and you'll see that the site has a lot of backlinks. That's what's getting it the ranking -- not how "on theme" it is.
Even now, with all of Google's "smarts", it's all about the links.
Keywords: baby names
Rank: #3 in Google
Do you find it hard to believe that a government site ranks #3 in Google for such a competitive term like "baby names"? It sure does, though, despite the fact that Google says that only 33 pages of the 24,900 page site are related to the topic "baby names".
Can sites rank well even with diverse themes existing on the same domain? The facts say yes. How do you do it? You need links.
Keywords: business cards
Rank: #8 in Google
According to Google, creativebits.org has 3,460 pages related to "business cards". That's about 20% of its 16,300 indexed pages. So, is this site about business? Or maybe finance or investment or small businesses or something that's related to "business cards" in some way? Nope.
What is the main site about? The site's title tag says of itself:
"creativebits | Apple oriented design community"
It's a blog about Mac-based graphics design software. So how does a site about Mac-oriented graphics software rank for the phrase "business cards"?
Links, of course! Take a look at the backlinks in Yahoo and you'll see it has thousands of them. And, incidentally, if you do take a look at those backlinks -- they come from pages having nothing to do with business cards (or business in general).
So if a page of content devoted to a highly competitive phrase on a site whose theme is completely unrelated to the phrase itself ranks for that very competitive phrase, can it really be said that Google requires a site to be all about one theme?
One thing that does seem to hold true, though, is that if you're going to have diverse themes on your site, you need
to separate them into their own subdomains or subfolders. That seems to help Google know that the "theme" of that
folder or subdomain is different, and to treat it independently.
Myths are Dangerous
All of these myths are dangerous, because they get people focusing on techniques and methods that simply aren't really effective.
That said, is it a bad thing to make sure that all of your links come from sites with similar themes? Or is it a bad thing to make sure the content on your site stays on theme? No, it's not bad. Going forward, Google may in fact take those things into account more.
But don't be surprised when you are out-ranked by sites whose content is not devoted to the theme, and whose links come from all over the map!
I've found that most of these kinds of SEO myths are propagated by people who are failing in their optimization attempts. They make blanket statements, backed up by vapor, out of frustration for their own failed attempts. "Google must require themed-backlinks because my sites isn't ranking well and I have a lot of links!" That kind of logic is faulty.
It makes much more sense to listen to the facts, facts like the ones I've presented here. Which sites are actually ranking well now, and what are they doing to achieve those rankings? Focus on what's working, not on the myths spread by people who can't seem to make it work.
So what's working? Getting a lot of one-way links pointed at your site containing your keywords. That's the short of it. There are some other things to keep in mind, like making sure the links grow slowly over time and don't all just suddenly appear on hundreds of sites, and making sure that you vary your link text so that it looks "natural". But the bottom line is, at least for the present, you need a lot of links.