It's not scientific in any way. I basically post the survey on Thursday mornings on the home page, and take it down later that night. I ask people if they are bullish or bearish for the following week. I also email out the link to anyone who wants on the list - although we do exclude premium members from that email just so we don't get back the sentiment of our own services since it may be biased.
People can use the info however they want, but in general when sentiment type surveys are showing extremes, it's generally an indication that things may be about to change since retail investor surveys are considered "dumb money" indicators.
In more recent years I have noticed that our survey has become more of a "smart money" indicator, for whatever reason, meaning, it has been fairly accurate and not as much of a contrarian indicator.
There's not much more to it than that. The AAII has a similar survey and it is also considered a "dumb money" survey, and the results are whatever someone wants to make of it.