The relationship between factions amongst these two categories (of Jinn and Men) of seeking mutual benefit from each other is mentioned in the verse:

وَيَوْمَ يِحْشُرُهُمْ جَمِيعًا يَا مَعْشَرَ الْجِنِّ قَدِ اسْتَكْثَرْتُم مِّنَ الإِنسِ وَقَالَ أَوْلِيَآؤُهُم مِّنَ الإِنسِ رَبَّنَا اسْتَمْتَعَ بَعْضُنَا بِبَعْضٍ وَبَلَغْنَا أَجَلَنَا الَّذِيَ أَجَّلْتَ لَنَا قَالَ النَّارُ مَثْوَاكُمْ خَالِدِينَ فِيهَا إِلاَّ مَا شَاء اللّهُ إِنَّ رَبَّكَ حَكِيمٌ عَليمٌ

And on the Day when He will gather them (all) together (and say): "O you assembly of jinns! Many did you mislead of men," and their allies amongst men will say: "Our Lord! We benefited one from the other, but now we have reached our appointed term which You did appoint for us." He will say: "The Fire be your dwelling place, you will dwell therein forever, except as Allah may will. Certainly your Lord is All-Wise, All-Knowing." (Al-An'am 6:128)

Ibn Taymiyyah comments on this verse (an-Nubuwwaat, pp, 311-312, through Fath ul-Mannaan, a compilation of the writings of Ibn Taymiyyah on the Jinn):

As for magic and soothsaying, then it is from the assistance of the devils to the sons of Adam, for the Jinn inform the soothsayer (with information) and likewise the magician, he kills or brings about illness or levitates in the sky through the devil's assistance of him. And so their affairs depart from what human's consider the norm by way of the devil's assistance of them ...

Then he quotes the above verse, then he continues:

For the Jinn and humans, they sought benefit (utility, pleasure), some of them from others, so these ones used those ones, and those ones used these ones in many affairs. All of them did for another whatever his objective was so as to aid in his objective, and magic and soothsaying (fortune-telling) is from this angle.

And thus, the Jinn seek their benefit through the magicians which is the desecration of the sanctity of revelation, prophethood and the religion, and the magicians seek the utility of the Jinn in bringing about or repelling harm, or seeking fame, fortune, power and the likes.