Notification Database - Social Sites

I am finding it sort of daunting working with Notification to make it work like facebook.

This is what I have:
Notifications table

notificationid int
notification varchar
createdate smalldatetime
memberId int --member id of the person causing the action

NotificationViewHistory table

notificationid int
memberId --id of the member seen this notificationid

I did take a look at the schema how facebook is doing it. apparently they seem to be saving the entire message in html/plain text format.

If i look at linkedin, they seem to save notifications for different parts of the website in different tables. for groups, profile etc.

i am trying to have something that will allow me save minimal amount of data on database tables.

anybody got suggestions?

email feature is redundant in this case for me.

So in the mailbox from the application itself?

this is mainly intended for users to get an update on their friend activities.
I guess this same thing could be used for email notifications as well.

This Notification, does it take place by email?