Trending on Twitter seems to be a big mistery. It is not really that complicated. If you run a business with over twenty people then all you have to do is have a conversation. Tweet with your main account then have the others discuss, the employees could tweet questions or replies. Keep this up for at least 15 minutes using your branded hashtag. If you have a customer base then tell them about it and ask them to use the hashtag, bam Trending.
Now what to do with those people, well you should funnel them to your youtube channel or website. Get them to take some type of action, Trending by itself is useful because it gets you exposure and some seo value from the tweets.
Smaller business? Just get your customer base to help. If you have a good relationship with them it should not be hard.
Btw Check out Vector Marketing for some marketing tips.