The relatively poor sales of the TNIV have been documented elsewhere. Now while these figures may be skewed (e.g. sales on Amazon are not accounted for), as a regular reader of this fine translation, I am somewhat troubled by this. The TNIV needs a re-launch and a re-brand. Here's what I'd recommend Zondervan do FWIW:
1. Scrap the name TNIV. It's almost a 'soiled' trademark to some and needs ditched. Wayne Leman suggested (in the comments section of the above link) that it be called the NIVu (u - updated), rather in the same spirit of the NLTse (second edition). I like that.
2. Scrap the NIV. Just stop making them. Put full weight behind the NIVu.
3. Give it a radical translational make-over. Be more free in some parts and more literal in others, like a gender-accurate HCSB. For example, on the literal side, change "sinful-nature" to "flesh" every time it occurs in the TNIV; change Romans 1:5 to "obedient faith"; change John 17:6 to "I have revealed your name"; change John 17:11 from "protect them by the power of your name" to "keep them faithful to your name"; change 1 Timothy 3:17 from "all God's people" to "the servant of God"; change 1 Kings 18:27 from "busy" to "relieving himself".
On the free-er side change Romans 3:25 from "sacrifice of atonement" to "wrath bearing sacrifice"; include verse 21 with the rest of Ephesians 5:18-20 (like the NLTse); change Matthew 6:9 from "hallowed be your name" to "may your name be regarded as holy"; change "LORD Almighty" to "LORD of heaven's armies" or "Yahweh over heaven's armies" everywhere in the OT.
4. Have mouthwatering editions for pastors/bible-geeks. Stop producing mainly crappy kiddy/teenager versions. Make them so beautiful that pastors have GOT to have one (ooh forbidden fruit). Have various quality bindings like goatskin, calfskin, pigskin, deerskin, etc. Use quality paper with minimal bleed through. Don't do red-letter editions; they are theologically suspect and horrible to look at. Have wide margins, single column setting with a sans-serif font; oh and do have smith sewn pages. In fact, Zondervan could do no better than appoint J.Mark Bertrand as head of production quality.
5. Produce a new study edition. Forget the old NIV/TNIV Study Bibles. Produce an NIVu Study Bible. Get D.A Carson to head this up (he doesn't like study bibles - tell him he has full control of notes). Failing Carson, Doug Moo would be the man. Assemble a dream team of scholars and produce a study bible that will blow the rest out of the water.
6. Re-record the Bible Experience in the new translation and offer it as a dirt cheap download (e.g. $10). The B.E is the greatest Bible recording ever. If they re-make it as a cheap download, the amount of people potentially exposed to the NIVu will be massive.
7. Have a decent web-service. Commit some people to managing a blog devoted to the NIVu. Don't let it get into a state of dis-use like previous TNIV offerings.
8. Find the most conservative pastors/teachers who like the NIVu and get them to promote it. Make detalied promo videos involving these guys. I'm thinking Keller, Carson, Stott, etc. Get the hearts of the pastors and the sheep will follow.
9. Seek wide consultation for translation changes. Invite the TNIV/NIV's most prominent critics on-board for translation suggestions. For example, N.T Wright isn't exactly a fan. Ask him for his input.
I am neither a marketer, nor the son of a marketer, but these suggestions are hardly rocket science.