Pogo Sticking refers to a specific set of actions taken by visitors who come to your website via a search engine.
If an Internet user sees your web page in the search results of Google (or a similar search engine) and clicks through to visit, then clicks the back button and returns to Google, then clicks through to a different web page in the search results, then clicks the back button, etc, etc. - this visitor is 'Pogo Sticking'.
They are bouncing away from Google's search results, back again, away, back again, and so on.
When a search engine sees this kind of behavior happens often for a specific search term it knows that its search results are not bringing up content which meets the needs of users and they know that they might need to experiment with other results to see if they can improve user experience.
Pogo sticking is inevitable in some scenarios. Users thinking of purchasing a certain product are likely to look at a number of websites before coming to a buying decision. Very few people will purchase from the first online store they come across just because that store has the product they are looking for. They may want to search further to compare prices, reviews or after sales care offers.
However in the field of content Pogo Sticking is a much clearer signal that the current ranking websites are not meeting, or only partially meeting, the needs of the people searching.
Google has been very specific that this 'needs met' approach is a fundamental aspect of assessing search results. It is part of their publicly available guidance notes that they give to their own staff who manually test the quality of search results. However they claim that it is not part of their core algorithm.
The SEO community is fairly split on whether or not Google is telling the truth here. From my experience they aren't!
In numerous cases I have seen ranking increases after reducing bounce rates and increasing dwell time on landing pages by making them more comprehensive / promoting Call to Actions / improving readability / etc.
I see the reduction of Pogo Sticking as an essential part of SEO, not just because of my experience but because it simply makes sense to spend some serious time finding ways to make your visitors want to stay ... its one of the most fundamental ways to get more conversions