We have a newer algorithm that will work with existing EventLogging and that will select more visitors to display the banner and hopefully get more users to participate in the survey.
This task has now been completed, the details are copied here from an email I sent out today:
The Discovery Portal Team recently completed a second running of a survey on the Wikipedia.org portal, using a non-intrusive banner, from June 13 through June 28, 2016.
Our goal was to target those visitors that arrive at the portal page but don't actually do anything, as these "non-action" page visits account for about 43% of the portal's daily pageviews. We also wanted to see if we could get additional respondents to the survey by using a different bucketing system and running it for a longer timeframe.
We wanted to see if the results would indicate that many visitors have wikipedia.org set as their browser's default home page. Our thinking was that the non-action pageviews are occurring because each time a visitor opened up their preferred browser, their homepage would display the Wikipedia portal page but the user simply goes onto a different site without using the portal first.
The resulting data was very similar to our first running of the survey in May 2016, as shown in the following graphics - displaying the breakdown of the June survey and also displaying a comparison of May vs June survey results.
I've also included a sanitized pdf of all the 'other' answers to our survey, for those curious about the content of the free text answers that were collected. Some of the responses are fairly humorous "I took the 5 oclock train" and some were a bit more serious "I typed in the URL of the website. Not the word "wikipedia" but "http://www.wikipedia.com". It's how I normally navigate to a website I know the name of." and we received plenty of love too "I love ❤ your site".
Our goal of trying to get those non-action visitors to do an action (namely to take our quick survey) probably failed miserably but, on the other hand, we received a lot of other really good information that will be quite useful to our future updates to the Wikipedia portal.
All documents used for this update/comment have been uploaded to Commons: