When we talk about the greatness of Vishnusahastranama ...lets recollect the setting... we know that it comes in the epic Mahabharata....it comes in the Anushasanik Parva of Mahabharata...before Anushasanika Parva is the Shanti Parva, containing 15000 verses all told by Bheeshma to Udhishthira explaining all there is to know about dharma in three parts...Rajanushasanikparva , Apaddharmaparva, and Mokshadharmaparva. This doesn't end here and continues in Anushasanikparva... but before Pitamaha Bhishma goes on to Vishnusahastranama lots of other things are explained...

there are details about atithi satkara, he talks about karma fala, then he talks about superiority of free will over fate ( purushartha over daivam) don't think you are a victim , you have a role to play. Then he talks about where all prosperity (lakshmi resides and where all she does not). Anushasanikaparva also gives us Shiva Sahastranama, it talks about teerth mahima, Ganga mahima (glory of the Ganges) , talks about importance of stree raksha. How women should be protected in the kingdom..then vivaha dharma..weeding as a dharma, then there are lot of details about go mahima(cow worship) protection of cows. Story of Nachiketa comes here in the Bharatam..Nachiketa overcoming death, story of Kartikeya, Muruga utpatti, Tarakasura vadham comes again, then shraddha karma is also explained in detail like tithi, nakshtram for shradham. Grhasthashram dharma, upavasa then demerits of himsa, demerits of mans bhakshanam( non-veg) are explained. Then various types of dana like swarna (gold) dana, go dana, bhoomi dana, kanya dana, vidya dana ...glory of all these dana is explained. Then it also talks about death and punarjanma,then about moksha dharma, then about vairagya...in trying for salvation main thing is vairagyam so vairagyaprdhanata is explained. Then pashupata yoga, shivalinga mahima, shivalinga pooja mahatmya. it also talks about Shiva and Parvati's conversation on stree dharma which shiva tells parvati to explain because he says that if a lady tells only then the other ladies will listen. After that is vishnu mahima .....

And then comes Vishnusahasranama.....