Producing content on HubPages might sound strange to someone runing a blog seriously, as I try to do, but there are indeed three reasons making it worth.

Write outside your niche

A blog usually address a specific niche and builds a community of readers and subscribers interested in this niche. Occasionally some posts can be slightly off-topic, but not too much.

So what if you want to write about something that is clearly out of the scope of your blog ? Given the hard work it is to create and make a blog popular it is not possible to run too many of them seriously. Moreover you need more than just an idea or willingness to write about a topic, a blog requires consistent content over time.

Is that a reason to drop all "collateral" ideas ? With HubPages the idea is clearly "No". I published hubs on a wide variety of topics, most of time answering requests, but also spontaneously, just to publish on the topic of the day.

Experiment new topics, techniques, styles, tones

One of the hardest thing to do when publishing a blog is to find your "voice". The tone, style, way of writing are an important part of a blog's identity and this is what makes it easier to identify for the readers.

Once a blog is well established, it is hardly possible to experiment with the voice. One can slowly change it, but publishing "UFO-ish" posts can have strong effects.

As HubPages do not create the same kind of discussion between authors and readers, it is much more each to experiment, publish Hubs in completely different styles and tones. I thought once of publishing a Poem hub, but I'm not good enough at writing verses.

Promoting your blog

Last but not least, as getting exposure is quite easy with HubPages, it is a good tool to promote your blog. Do not publish a promotional Hub, it would not be well perceived (and probably removed). One good way is to create a Hub about your niche, or a topic in your niche with various resources, including the blog you want to promote.

Less dialogue

I see some of my blogs as dialogues with a community of readers. Even if HubPages allows for comments, RSS subscription and so on, it is a less personal enviroment. It is not your site, it can not be fully customized, and so on.

I published several Hubs which later lead to long discussions in comments, but it is not frequent to see cross-hubs comments. This is also probably because I write here on a wider set of topics.

Flexible but limited

The HubPages publishing tool is relatively flexible regarding layout in each hub, but don't expect too much. It is not possible to fully redising it to your very personal taste.

Moreover (correct-me if I'm wrong) there is no way to add HTML or script elements, like own stats, other affiliate programs than what is offered by HubPages (AdSense, Amazon, eBay).

Less promotion needed

I never said you don't have to promote your hubs, but as HubPages works like a community with fans, requests, and so on, it's quite easy to get traffic on a new hub.

This is particularly true if you answer a request, because at least the requester will check it, and possibly other hubbers that are potentially interested in answering it after you.

I sometimes published hubs on what was my "topic of the day" and got a surprising number of views without any promotion. Note that this would probably not work if you hub is about growing oysters in zero-gravity...

Loss of focus

If you're very creative and likely to write about any topic, the rest of your blogging work can be harmed by starting a Hubber career. There are dozen of new requests daily, the community is really quick to comment, so the risk of no longer working enough on your main blog is really serious.

Loss of identity

Bloggers always try to make their name or blog name strongly associated to their topic - including in search engines. If you cerate Hubs using the same identity, it could become less clear to your readers.

HubPages is search-engine friendly, so ask yourself about your username. The purpose of a pseudonym is not to fake readers, but to make sure what you publish here do not interfere with your image as a blogger.

I personally uses two identities here: this one (Rod Beglerf) for publishing on various topics, and when I publish hubs related to my best blog which is very niche-y I use the identity I developped there.