Despite feeds becoming a regular part of web sites, people continue to struggle with how to use them, and don’t want to have to schlep from site to site to find feeds that might interest them. Enter topic-based readers. With these services, you don’t need to seek out sites that cover the topics of interest to you. Instead, search for those topics and the service delivers what it thinks best fits your needs.

I’ve yet to find two sites offering topic-based aggregation doing things the same way. So your best bet is to try out the different services and see which suits you. The features you will most likely want to look at are topic selection, usability and “scannability.” You’ll discover that some sites are easier to use than others, while some do a better job of selecting and saving topics. The following four sites deliver content by topic to simplify your task of receiving content that interests you (Twine is another topic-specific aggregator that we’ve covered previously.)

ensembli

Your ensembli dashboard is divided into three zones: “Follow,” “Discover” and “Explore.” “Follow” lists the topics you’re following. “Discover” lists the latest articles about specific topics. You can rearrange and delete topics at will. Every headline in the “Discover” zone comes with a summary; email, Twitter and Facebook sharing options; a link to read the full story; the ability to “favorite” the article and the option to delete it. If you’re not looking for anything specific, then you might want to head to the “Explore” area for a list of hot topics and editor’s picks.

The well-organized dashboard makes it easy to navigate and use. The “Discover” section needs more rich content, as the current selections only return okay results, but the service is still new and undergoing improvement.

Evri

Evri, currently in beta, splits its contents into two main sections: one showing your current topic or collections and the other splitting the content into different types such as articles, images, videos, quotes and tweets. However, the service only offers a limited topics. For example, if you want to search for freelance-related topics, instead of retrieving articles about freelancing, Evri delivers content related to companies, brands, people and web sites.

While the service does have some conceptual topics like “small business,” “cash flow” and “email marketing,” its major focus is on people and companies.

The topic page has a cool visual that shows your current topic and its connections to other topics:

This demonstrates the limited topic selection. The “Small Business” map shows connections to companies, countries and products; nothing about finance, management or strategy. Evri is probably best suited to research on companies or individuals, not conceptual topics. It also has a few usability quirks, such as taking too many clicks to get where you want to go.

Guzzle.it

Guzzle.it is similar in approach to popurls. The aggregator posts all your topics and a handful of headlines in columns for easy scanning. Enter the keywords for your topics, and arrange the topics however you like. For trend followers, the service includes popular headlines, as well as the latest images.

The quality and accuracy of available headlines is mixed. Some articles are on target, while others don’t come close. You can’t delete any of the articles to improve your results or view more results — even though some high-quality sites might have more recent articles than those showing in the results. Guzzle.it does a good job with its organization, topics, customization and usability, but could stand improvement on the provided content. For example, the topic “writing” has results including articles on a business reporting financial losses, vintage coats, programming and Canadian town halls.

Lazyfeed

Lazyfeed provides live updates for your selected topics. The topic of “Writing” produces related subtopics of poetry, marketing, copywriting, business, books and so on, in order to narrow the topic’s results — a great feature. After browsing and discovering a topic you like, you can save the topic to receive real-time updates. When a topic receives an update, it moves to the top of your topics list. Getting around the service takes no time with its minimal design and status bar navigation.

You can block a site if you don’t like its content, but you can’t delete articles to move them out of your way. If you find a poor quality site, you can block and report the site.  Lazyfeed doesn’t like more than one word in topic titles, so instead of “social networking,” you’ll need to use “socialnetworking,” for example. Annoying, but it produces good results. You can read most articles of interest right inside Lazyfeed and share them on Twitter, Facebook or by email.

Lazyfeed has an original feature that allows you to “connect to a site.” You can connect to Twitter, Flickr, Delicious and blogs; once connected, results from those sites will start to feature in your feed. The very impressive Twitter results show hashtag topics, along with extra notes.

What content aggregator do you use? What do you like about it?

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Why iPad 2 Will Lead Consumers Into the Post-PC Era
• The Near-Term Evolution of Social Commerce
• Content Farms: The Players, The Benefits, The Risks