There are TONS of reasons that SERPs (search engine results pages) change. Here are a few common ones.
If you usually search for “my business – Vancouver” and the next day you neglect your second cup of coffee and the ” – Vancouver” on your search, the results will be different. Search engines are getting wiser so there shouldn’t be huge differences if you use the same words, but in a different order. For example, “WordPress websites” and “websites in WordPress” return the same results in the top three spots. But vary from then on.
You may have been coasting along beautifully until one day, you’re no longer on the front page. But your rivals across the street are in the top spot. A possible reason can be that they’ve spent time and effort improving their site. If you spend time and effort improving your site, and yet your rivals still beat you, it could be that they’ve spent more time and effort. It could also be a number of other factors.
Websites that are gaining traction fast and have been around awhile and are well-done and optimized for search engines will do really well. They just will. The answer is that you have to be gaining traction, have a well done site, constantly work to provide valuable content and optimize the site for search engines.
If you’re not using these guidelines with a focus on site longevity, and Google catches on (which they will – they’re Google, after all) you’re dead in the water. The Answer: Respect the guidelines. There are no shortcuts. Do your work to gain attention of your customers and create a site that is search-engine friendly.