Lord Ganesha is the son of Lord Shiva and Parvati devi. He goes by other names like Vinayaka and Vighneshwara.
If we look in the etymology of the name “Ganesha”, it is formed by Gana + Eesh, where Eesh is short for Eeshwar, which means Lord. So Ganesha means lord of Gana. Gana means body of attendants, here referring to the huge retinue of Lord Shiva. And remarkably the Ganas are also known as Bhutagana, because Shiva is the only god anybody can go to. So all the rejects of the society get attracted to the matted hair and smoking dope god. Quoted from wikipedia,
the gana or bhutagana are attendants of Shiva that reside in chthonic and liminal locations such as cemeteries and charnel grounds.
In fact it is not long when Lord Ganesha was seen as Vighneshwara. Which means lord of obstacles. And he was seen as the god who creates obstacles if not pleased. So if you don’t appease him before any endeavor he might as well create obstacles. Which in time changed to the feeling that he protects you from obstacles. Quoted from new world encyclopedia,
As the “Lord of Obstacles,” Ganesha is responsible for creating obstructions of both a material and spiritual order. It is he who places obstacles in the path of those who need to be checked. Thus, Ganesha is thought to be the gatekeeper of shrines, and he is said to corrupt all those who are unworthy of entering such holy places by further deluding their minds with desires.  Ganesha can also remove obstacles for his devotees just as easily. Ganesha’s diametrically opposed functions as both obstacle-creator and obstacle-destroyer are vital to his character, giving it significant depth as he is venerable for both negative and a positive reasons.
This change in emphasis from creator of obstacles to protector from obstacles is accompanied by change in iconography. This is a painting from the 15th century, notice the number of weapons, and the fierce expression :
What can the marketer learn from this? That a brand identity can be changed, and in fact to exactly something diametrically opposite. How many marketers in today’s economy can claim to have achieved such a feat?
I can go on to other lessons you can get from Lord Ganesh, like the fact that the Ganesh Chathurthi celebrations in India was engineered so that, quoted from wiki
Lokamanya Tilak visualized the cultural importance of this deity and popularised Ganesha Chaturthi as a National Festival “to bridge the gap between the Brahmins and the non-Brahmins and find an appropriate context in which to build a new grassroots unity between them” in his nationalistic strivings against the British in Maharashtra.
Do you see any parallel between this and the many Days the greeting card companies have started promoting, from Mother’s day, Daughter’s day, Father’s day, and so on?