Query suggestions

I have situation like below and i answered it like follows. I did count of emails. But what is SUMEMAILCnt ? And also an efficient way to count a billion rows which i never did. PLease help me with your suggestions. Thanks in advance.

There are 3 tables.  UserProfile, UserProfileClick, UserProfileEmail.  UserProfile stores information about a user’s profile.  UserProfileClick stores a record every time someone clicks on a user profile.  UserProfileEmail stores a record every time someone sends an email from a user profile. 

UserProfile
UserProfileID	CreateDate	ProfileName	EmailAddress
1	5/1/2013	SeattleBrian	SeattleBrian@NoWhere.com
2	6/1/2013	KimOverHere	Kim@NoWhere.com
UserProfileClick
UserProfileID	SessionGuid	DateTime
1	0000059f6b18435ead3869a10b240616	8/1/2013
1	00001bc8c95f44a281be2f37b82b34db	8/1/2013
2	00002213-0221-4758-a088-35075c79e2e7	8/1/2013
UserProfileEmail
UserProfileID	SessionGuid	DateTime
2	0000b885-6854-4131-8b93-631c83bb35f7	8/1/2013
2	00010c51e820408e9ec4839fe84b7f8f	8/1/2013
2	00012926-5f93-4272-9cc2-ae9ebf7825f1	8/1/2013
1	000114fa0aa441e5bf667e881194e75a	8/1/2013

Need a query to show the ProfileName and the SUM of all Emails and Clicks.  Results should be

ProfileName, SUMEmailCnt, SUMClickCnt.  These tables are rather large with around 1 billion records in each of the Click and Email tables.  

Answer:

select UP.UserProfileID AS PROFILE_NAME
, COUNT(UPE.SessionGuid) AS EMAIL_COUNT
, COUNT(UPC.SessionGuid) AS CLICK_COUNT
from UserProfile UP, UserProfileClick UPC, UserProfileEmail UPE
where UP.UserProfileID = UPC.UserProfileID AND UPC.UserProfileID = UPE.UserProfileID
GROUP BY UP.UserProfileID 

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svk