I received an e-mail from a reader who was interested in a post talking about bounce rate, and how that might be used by search engines as a possible ranking factor.
The concept is that a higher bounce rate would be seen as an indication that a site is of relatively poor quality. For example, does a bounce rate of more than 70% mean that you have a bad site? Thats pretty high, right?
Bounce Rate Definition
First lets start with a definition of what it means. There are two possible definitions – one is how long the user spends on your site. For example, if they on the site less than 15 seconds, it is considered a bounce. The other measurement is the number of page views by the user during their visit to your site. For example, they see only one page and leave.
Your analytics package uses the page view approach, because they cant measure time on site, because they dont know how long you spend on the last page you visit. A search engine, however, does not know how many pages you visit (unless, using Google as an example, they leverage the Google toolbar or Google Analytics data), but the search engine can tell if you did a query, went to a site, and you were back at the search engine doing a query again 5 seconds later.
So what is an acceptable bounce rate? As with everything else on the web, the answer is that it depends. For example, if you have a reference oriented site, and the user gets the answer they are looking for as soon as they get to your page, they may simply leave. This is an example of a scenario where the fast exit from your site is actually an indicator of quality. The user got what they wanted very quickly.
Do search engines use Bounce Rate as a Signal
Do search engines use this as a signal? It is certainly possible that they could. They all have the ability to collect data by various means. They certainly have the ability to see how long (or short) the interval is between visits to their search engine. I asked the question of Matt Cutts and all Matt would say is that the signal was potentially a noisy one, meaning that it would be prone to error.
If they do use it as a signal, various types of filtering would need to be applied. For example, you would want to look at classes of sites in the same category as one another and compare their bounce rates. If Ford Motor Company has a higher bounce rate than General Motors, that might mean that the GM site is a better site. However, you would not want to compare the Ford Motor Company site to the Amazon web site. Their businesses and web site goals are just too different.
Another things you can do is look at many different signals together. For example, you look at bounce rate, and you look at bookmarks, you look at social media tags from sites like del.icio.us, etc. Each signal by itself maybe noisy but you dont treat any one signal as an indicator. Instead, you look at the cumulative weight of all the signals together. In other words, if one signal says something negative, it doesnt really matter. If 3 signals all look negative, you now start using it as ranking factor.
My sense is that bounce rate is something they use in a filtered manner, perhaps as I have outlined above. It does provide information, but it must be used judiciously. When signals like this are misused it can lead to lower index quality. All of the search engines want to highest possible quality index, because that leads to market share.
Dont forget usability
Last, but not at all least, dont forget about usability. High bounce rate may be an indicator of usability problems on your site. If you have a 70% bounce rate and you may be able to do things to make the site more functional for users, you may be able to lower the bounce rate to 60%. This could lead to a 33% increase in conversion – which is not something to sneeze at.
The usability perspective is the best one to use in evaluating bounce rate. You potentially get two wins for the price of one. More visitors from search engines, and a higher conversion rate. For that matter, a more usable site is more likely to get tagged more often on del.icio.us and other social book marking sites too.