Make or Buy

In the BusApps space the old and actual question is related to the Make or Buy dilemma.

I have a clear idea about it, but I would like to get additional contributes.

The only thing that I can say it that probably there is no an unique approach valid for CRM and ERP, but we need to mix them.

What do you think?

-roberto

PS: there are a lot of CRM books already published, but I'd like to write a new one to summarize my thoughts/theories. I saw a lot of books related to the CRM genesis and theories but no one related to REAL field experiences!
What do you think?