I am a Realtor, and use both OUTLOOK and Top Producer software.  TP7i is
where all of my contacts get entered.  I can send email from either product.  
My cell phone has a voice dial feature which reads my Outlook contacts only.

I need to have software which can keep all TP7i contacts updated into
Outlook without me having to manually select which ones to Export/Import.

I'd like this to happen with each Hot Sync I perform.  (Read TP7i online
database, compare w/ Outlook, update new and changed contacts into Outlook,
with replace duplicates with imported items.)

This can be sold to all Realtors who use both products.

And you could design a similar product for ACT! for people who use that.