Maintain a strong flow in writing, among other things
"Sentences are cohesive when the last few words of one set up information that appears in the first few words of the next. That gives us our experience of flow." Joseph Williams, page 58
Transitions are arguably the most important part of any piece of writing, long or short. I think it's especially important in journalism, where your space is limited and there's restrictions on space. In order to better utilize that space, a good writer will transition seamlessly from one sentence to the next and avoid having to introduce each point at the beginning of every new sentence. Every well constructed transition can save as many as five words, and over the course of a 500 word article, that can amount to an additional three to five sentences of valuable information that you might not have otherwise been able to include.
In addition to saving space, transitions help the reader smoothly scan through your writing. When writing becomes too dense and choppy, it irritates readers who will decide that your writing is just a waste of their time. Readers are most happy when they can absorb a lot of information quickly and if your writing has good flow and cohesiveness, this comes both easily and naturally. It's a fast paced world and your writing needs to keep up with that making good flow all the more important.
One final point about good flow is that it can actually force your audience to continue reading your piece because no good spot can be found to stop until the end. By setting up every upcoming sentence at the conclusion of the previous one, the reader subconsciously forces him or herself into continuing on to the next point to reach some finality. The good writer forces readers to do this over and over again until the end of the story. It can be very difficult, but mastering transition techniques can greatly benefit your writing.