There are many silicone compounds out there, and I believe most of the generic goo that you may get with hardware is silicone-based. There are also ceramic compounds, which have ceramic particles in a suspension and are better than silicone, and also metal compounds (usually silver), which are the best for cooling(eg. Arctic Silver 5).
That stuff doesn't look like it'll give you the best cooling in the world, I think you could class silicone as a non-designer compound.