Wouldn't paid ads put their "not-for-profit" status in jeopardy?
That is the key. If jw.(B)org accepted solicited UNPAID adds from businesses for which they suggested ordered that the sheep patronize for some token discount (remember, most JW's are tightwads) they could accept a cash kick-back donation from those approved businesses.
What a wonderful arrangement from the GB...JW's think they got a deal on something, the organization gets money coming in, and businesses get a tax break for "charitable" contributions.