Google Trend, page-11

https://trends.google.com/trends/explore?date=today 5-y&q=redbubble,society6

Further to guy's original post in this thread, it's interesting to compare the Google Trend of Redbubble and a similar, privately owned competitor Society6.  It shows the difference between what has been a seasonal bump and what could be read as strengthening by Redbubble (at least growth in number of people searching for it).  

Both had a seasonal Christmas shopping/Thanksgiving/Black Friday bump, but whereas Society6's trend chart looks very similar to the last few years', Redbubble's is significantly different.

This also applies in a less neat way to Etsy.