Competition

I was just thinking about something yesterday.  We are in the carpet cleaning industry, but the manufacturing and repair of the machines(WE DONT CLEAN CARPETS).  There are companies all around that clean carpets but also do the repairs and sell chemicals for other companies to purchase.  Why would you want to buy products and accesories from them if they are probably the ones putting the smaller companies out of business.  Why feed the fire that kills?  I just dont get it.  Will somebody tell me why they purchase from there VERY OWN COMPETITOR???