Google recently announced a long list of search engine algorithm changes and tweaks they performed in March 2012. SEOs and others who closely monitor their search engine positions reported a lot of volatility in the SERPS in March and there are a few areas in particular that Google targeted that would be primarily responsible for the changes in positions.
Google was conceived and developed around the central idea that a link to a web page is a vote of confidence that the content on the page is probably of good quality and therefore the page is worthy of being included in the search results for a query for keywords that are found on that web page. That has not changed and Google is always looking for ways to improve their ability to identify which are the best links that merit consideration. In March they made some tweaks in their handling of a link’s anchor text (the visible words that one clicks on) that allows them to better interpret and use this anchor text.
This may be the biggest factor in the recent ranking changes as links are added and dropped from inclusion when considering the value of a web page. It is not just external links (links from other websites) that are affected but internal links as well. The link text that you use in your site’s navigation menus and links between pages of your website are very important too Google. There is some discussion that changes to how the link text of these internal links are handled may indeed be one of the biggest reasons for recent ranking changes. Optimizers have long known that link text of internal links were important and have optimized accordingly. Discussions amongst search engine optimizers show that they are reaching agreement that beginning in March many more of these internal links are being deemed over optimized by Google and this is resulting in ranking drops and even over optimization penalties.
Another area of change that would have had a big affect on ranking was in how Google treats synonyms. The synonyms that you use on your web page that relate to the keyword being searched can affect your positions in the search results. Google has made changes to how much weight synonyms are given when determining whether to return a web page for a specific search query. The indication is that they are being less aggressive in their use of synonyms and this too would affect sites that could perhaps have been over optimized.
Google has also made improvements in their ability to detect older stale web page content and in particular for blog and forum pages. This may have a bigger impact than is apparent at first. What it means is that blog posts that you may have written a few years ago with the idea that you were building this vast store of content that would allow you to appear for a multitude of “long tail” search terms have a shelf life. If you wrote an article three years ago about real estate in a neighbourhood you specialize in it may have resulted in a lead or two a few years ago but is unlikely to now. A newer article perhaps written by a competitor six months ago would be generating the leads now. Blogs are looked at as “news” by Google and not really as static content. For that reason it is probably better to have both a website and a blog for your Realtor web promotion strategy rather than using a blog format like WordPress to be both your website and your blog.
Google also made updates to what signals they use when personalizing the serps for each individual search. You should by now be aware that the search results are different for pretty much every single person that searches Google.
If your rankings have changed for the worse recently this gives you a few things to work on to get them back up. If your blog does double duty as your website you may want to evaluate that strategy as well.