Can anyone help me knowing to what extent does Marketo platform allows for deep segmentation of our database?
Thanks & Regards,
You're going to have to define your requirements exactly, as there is no established meaning for that term, AFAIK.
Smart Lists can do whatever you want as long as the data is there.
As Sanford says, you might want to give us more details on what you are trying to do.
And as Josh says, Smart Lists are very flexible and allow you to query data that is in your lead's profiles, Custom Objects, user's behaviour on your web site and when receiving your emails, etc... you can also add custom fields in lead profiles to match your needs, etc.
We'll be able to give you a more detailed reply when you give us hints on your use cases.
All above comments are correct. Segmentation can be done in many ways and I guess it all depends on how far along you are and what you want to accomplish. I wrote up a post on the basics of personalization which may help if you aren't already too far along in your Marketo segmentation (can be found here).
Otherwise I would recommend reading through the product docs, there's a lot of good stuff there when you're wondering how features work: