Question: I need to understand the fine details, possibilities and pricing of Salesforce OEM model. I can't find an official link about this on salesforce and google, only link available is this 2008 pdf : <http://www.developerforce.com/tdf/2008/april/Force_ISV_Partner.pdf>

Please share any good post/article on this.

Answer: 
The best non-record type solution I can think of is to have a time-based workflow change the owner. You could then use sharing rules to give other users read-only access to the records.

In addition, while extra record types might be cumbersome to maintain they still might prove to be the simplest and cleanest solution in the end.
I have used this syntax in a validation which has seemed to work well.

```
PRIORVALUE(LastModifiedDate) <> NOW()

```