Why not? Charles Taze Russell owned the printing company that printed the materials he wrote and then stated that the WTS itself made no money...
According to page 42 of the 1975 Yearbook of Jehovah's Witnesses, all materials were printed and bound by Russell's privately owned Tower Publishing Company for an agreed price, then distributed by "colporteurs" (persons who travel to sell or publicize Bibles, religious tracts, etc.).
In the January 1891 edition of Zion's Watchtower, Russell stated,
"The Society owns nothing, has nothing, pays no salaries, no rent, or other expenses. Its policy is to use in the work every dollar received, to the best advantage, and as speedily as possible. Its success in publishing and circulating among the right kind of readers, tons of the Old Theology Tracts, is phenomenal alike to its friends and its enemies. The latter imagine that there must be great wealth connected with the concern, whereas really there is very little.--Few of the friends of this cause do, or are able to do, much financially; but what money there is, under economy and the divine blessing, is like the widow's cruse of oil: it accomplishes about a hundred times as much as other Tract Societies, which spend most of their receipts upon salaries."