E-mail used to be about connecting people, regardless of distance. With time, it developed new capabilities - sending attachments of ever greater size, acting as a marketing vehicle, both solicited and otherwise (see: Spam), displaying pictures and HTML, and of course, serving as a repository for status notifications for commerce, news, and social media. Now, there's no question for me that updates from online services greatly outnumber the amount of person to person communication I get each day in my personal e-mail. (Work e-mail, of course, is another story)For me, e-mail is where I want to be updated for all things finance, be it bank statements, credit card invoices, stock trade transactions, or the electricity and cell phone bills. As I see it, every e-mail note there saves paper, and saves me digging through the mail to sign something off and send a check.
I also, despite getting them at an increasing rate over the last few months, still get notifications by e-mail when somebody chooses to follow me on FriendFeed, LinkRiver, Shyftr or Twitter, for starters. I also get notified if someone befriends me on other services, like Facebook and Digg. At times, especially when a particular topic is driving up conversation, I can hear the sounds of new e-mail hitting my computer every couple minutes, invariably drawing a sarcastic comment from my wife, who helpfully adds, "Well, aren't you popular?"

Twitter and FriendFeed follows come in pretty often these days...
While I could, of course, turn off these notifications, it helps to see if the person following is someone I'll be soon watching in turn, and it also alerts me to if I'm getting name-dropped somewhere. Usually, a quick visit to Summize or Google Blog Search can help with that.
Curious if others using Web services as I do were seeing a similar onslaught of Web notifications taking over their in box, I posted a question to Twitter, which also hit FriendFeed. So far, the response is certainly mixed.
Susan Beebe claimed 85% of her e-mail to be from "real people", but otherwise, the FriendFeed voting came out 16-2 in favor of services, while Twitter replies also came out with services ahead, 6 to 1. Bwana McCall wrote, "I get more Bacn than real email. It's sad.", while Hutch Carpenter said it simply, "Notifications by far."
While many people are fighting with the e-mail data deluge, striving for the proverbial "In Box Zero", handling online notifications is like any other system. You just need some good hierarchy. I've set up a folder called "Blog" in my e-mail for all correspondence related to the blog, from people pitching stories, to working with entrepreneurs and other bloggers. I have subfolders for some of the services where I've had the most updates, and of course, for real-world work, I have a "Commerce" folder, which surprisingly, has all my stock trade notifications from eTrade going back to the year 2000, and every Amazon.com order ever. Thank goodness for e-mail search, something Apple's Mail program does extremely well.While robots may have taken over the inbound side of my e-mail, I still own the outbound side, and take every effort I can to keep up. But the mix has definitely changed.
Not every social aggregator is on the path to riches or fame and fortune. Even the best designed, thoroughly coordinated sites can find the push to grow a user base and generate community difficult, especially as the number of similar sites spirals ever higher, driving a need for differentiation and specialization.
Unlike other sites which operate with you as the anchor, asking you to set up the many Web services you use and then share your profile with friends, 
Whether it be RSS feeds, social networks, or one of the many social media aggregation sites, it's no surprise that even your closest peers are sharing data they care about that you just don't. But so far, despite many users calling for content-based filters, solutions to block keywords or topics are missing from the vast majority of information spigots. In fact, I can't think of a single one I use that's gotten the formula right.
With the addition of movie rentals on