How can we show significancy of a company? How we can assure clients that the company has customers all over the world or at least all over the city, country, etc. A lot of designers receive such requirements from companies. And one of the solutions in this situation is to use our planet image in the logo so it will make some attractive Planet Logos. The Earth, a home for population at large, can bring globality for the brand.
And it is also very popular to use this symbol for travel companies. But it is very logical, just in logo they show what you can see with their help.