We have known for some time now, thanks to Search Engine Land editor-in-chief Danny Sullivan's interview with Google and Bing, that they use Twitter as a ranking factor.

So, if you're wondering how to make a better Twitter profile and influence search-engine rankings, you have to make sure you keep your account in good shape.

Here are seven ways to improve the SEO value of your Twitter account and tweets.

1. Find your target demographic

If you don't target a specific demographic from which you hope to gain followers, your social connections will seem random and unfocused, which harms how your tweets rank when you post about certain subjects.

When you tweet about a subject unrelated to ones you usually post about, those tweets appear lower down on the list of recent tweets, hurting your influence (I rank much better for #SEO than #celebrity, for example).

By following and being followed by relevant Twitter accounts, you increase your account's influence, ranking, and SEO power.

2. Write a bio to attract the right followers

Once you have your demographic in mind, write your bio to appeal to that target audience; doing so increases the chance that the right type of people will follow you.

I've often clicked on Twitter's suggestions of whom to follow (those deemed similar to me), only to see an off-target bio that makes me question the user's relevance; ultimately, I don't follow that person. Had the user had a description that was in line with my target demographic, I would have been more likely to follow him or her (in hopes of a reciprocal follow, of course).

When you include some keywords in your bio that people can search for, they can find you and they can determine whether to follow you. So, if you want people to find and follow you for being an SEO and social media professional, for example, include those keywords in your bio.

If you want them to find and follow you for loving beer, or living in Houston, or for knowing "How to make money online," include the relevant phrase in your profile.

3. Use Twitter lists

People who know how to use Twitter want to be on lists; after all, lists help them gain Twitter influence and SEO potential. By creating lists, you show people they have the opportunity to be on your lists, and they will sometimes follow you in hopes of being included (sometimes they even ask directly).

The lists you make should be a product of your target demographic. For example, I have an "SEO" and a "Social Media" list because those are my industries and target audiences. I suggest naming your lists simply by using the keywords you want to rank for.

Updating those lists as you go along, or every week or so, is a good way to go. You don't want your lists to look outdated or unused.

4. Do an audit of the people you follow

If you follow many more people than are following you, you'll harm your account's potential because most people will be less likely to follow you if they see lopsided numbers.

Also, lopsided numbers hurt the SEO potential of your account because to the search engines it looks like you benefit from others more than they benefit from you. Search engines "trust" someone who helps others more than they trust people who need the help.

In any event, why follow major Twitter users who have many more followers than follows? Many of them rarely post useful information and they tend to use Twitter mostly as a networking tool (and they are not networking with you or me).

Furthermore, it'll just add to your following list without getting you a reciprocal follow and could also clutter your timeline (stream of tweets by those you follow) with irrelevant posts.

5. Follow accounts that everyone in your industry follows

Twitter's suggestions are in part based on whom you follow and who they in turn follow. If you want your suggestions to work better, you need to follow some of the big-name accounts in your industry (for me, it's Google, seland, SEOmoz, Matt Cutts, etc.).

Though getting follows from those accounts can be difficult, they can be good sources of content and they make your social graph look more legitimate. Just make sure you do not overdo it by following too many who won't follow you back.

6. Eliminate the Twitter spam following you

Twitter spam hurts your follower list and can undermine your aspirations of having a high-powered Twitter account. Sure, the lofty follower numbers look nice (and the account pictures might look nice, too), but having spam accounts following you yields more bad than good. It clouds your social network and hurts your SEO and influence potential.

Watch out for people with no bio, picture, or tweets, or people who are following many more people than are following them.

Also, Twitter accounts that are tweeting only (or mostly) about their company's products and services are unhelpful to you (unless, perhaps, they are relevant to your industry).

7. Shorten your links yourself

There is nothing like seeing the power you have by viewing how many clicks your links get. Signing up for link shortening is free, and bitly.com comes with free basic metrics.

If you ever need to show numeric evidence of your influence (beyond followers), click data can be a great metric to show a client or to present on an interview. And considering it takes only a second to shorten a link, it is time worth taking.

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Those are my tips for running a better Twitter account; did I miss something big? If so, list your strategies in the comments section. And if you found this article valuable, share it, especially on Twitter.