While everyone has their opinions about Facebook's future and we've given recommendations on how to make Facebook useful again, there's no denying that Facebook is a success. Facebook's integration of search, aggregation, and conversation is a winner in anyone's book.

Search
Their search feature is very useful for exploring every nook and cranny on Facebook. These days, tracking someone on Facebook is as easy as finding that same person on Myspace. Facebook's search feature is stalking at its best.

Aggregation
Facebook has been great with aggregating personal content since its all exclusive launch. With the addition of a plethora of great Facebook Apps to help out, aggregation on Facebook has only gotten sweeter. They've recently opened up the Newsfeed to include web 2.0 services Flickr, Picasca, Yelp, and Del.icio.us. While we didn't think Facebook's news feed was open enough, it was a huge leap for Facebook. Coupled with the Facebook Apps that integrate Twitter, FriendFeed, and more into the service, aggregation is becoming a strong area for Facebook.

Conversation
There's plenty of conversation about Facebook and on Facebook. The Wall application is one of Facebook's most popular features and definitely enhances the service. Really, Facebook speaks volumes in this area, so we won't bore you with a rehash.

Twitter

Our beloved Twitter has received a lot of complaints in the past week for its downtime problems. Non-Twitter users even may wonder why we put up with the service. Three words: search, aggregation, conversation.

Search
The integrated search function on the Twitter site isn't all that useful. It took over a year for the feature to be implemented and like Facebook, Twitter apps do the job better. While search is basic on Twitter, search engines like Summize, Terraminds, and Tweetscan do more than enough to solve the various problems that Twitter's official search engine doesn't. With these search tools, you can better see what people say when they tweet, track your brand on Twitter, and more. In fact, two of these engines are Twitter's most popular tools, helping to make Twitter a killer service.

Aggregation
Twitter doesn't discriminate on what you can add to the service. Pulling in feeds from other sites and pushing them to Twitter is simple. Since Twitter doesn't do this by default, you'll have to use one of the many twitter tools available such as Twitterfeed. Grab the RSS feed of any service you'd like to aggregate on Twitter, plug it into Twitterfeed and you're good to go.

Conversation
Twitter is one massive conversation in itself. It's a communication tool so of course conversation is a focal point that Twitter is most successful at. However, what's so great about the conversations is the wide variety of topics and "tweets" being sent through the service. Content may be king for blogging, but conversation is the king for Twitter.

FriendFeed

FriendFeed is this year's Twitter, which was last years innovator. While FriendFeed may be a duplicator in some ways of other services before its inception, there's no denying that it's now the top social aggregator and a service that's gaining a lot of steam.

Search
FriendFeed is the child of some of Google's best engineers. Consequently, the search engine on FriendFeed is fantastic. Users have a multitude of ways to search for things such as going through your own aggregated items for something, searching your entire network of friends or one person, and even using the search to find something within a specific service.

Aggregation
FriendFeed is a social aggregator. What can't you import to FriendFeed if not through the various integrated services then via the "imaginary friend" feature? Enough said, don't you think?

Conversation
FriendFeed has some of the best conversations on the web. Not getting enough comments on your blog? Head over to FriendFeed to find them. Members of FriendFeed congregate not only around various popular blog articles, but also Twitter messages, shared items and more. In contrast to Twitter, FriendFeed's conversations are a lot more organized and logical. Where Twitter conversations can be noisy, FriendFeed conversations would be the exact opposite: valuable.

Continuing Success

Search, aggregation, and conversation are the focal points of today's web services. There are more blogs, alternative search engines, and aggregators then ever before. These are just a handful of services that have taken off. While these may be the keys to a great beginning, in our next post we'll follow up with the keys to expanding the success of a service. Until then, we'd love to hear your thoughts on what some other keys to success are and what keys help with the longevity of a service.