The quick and ease of responses from a huge panel of consumers. You can ask them anything from concept images to product liking. New question features such as grids are a big plus and extremely useful.
They are not global so that sometimes impacts the sources we can use.
If you are looking for a tool that can access a large amount of consumers in a short time period this is definitely a good option to pursue.
Being able to reach a large consumer base without conducting any external testing per say.