Infographics done right make information more digestible. That tends to attract a lot of attention - especially if it's about a hot niche topic. For example, I'm a cycling fan - if someone did an infographic on the Giro d' Italia (a big bike race going on now) I'd be all over it. Put it in front of the right audience and it'll get re-shared a lot.
They're also helpful because there are lots of infographic directories/review sites out there. If you can submit your graphic to those, you gain some easy links.
If you then make the infographic embeddable, you can pick up a lot more links and re-shares as folks embed the infographic in their own blogs.
Creating a good infographic requires real expertise in data visualization. I strongly suggest hiring someone else to do it for you. Expect to pay $3,000 or more for a real pro. I've seen them offered for as little as $1,000, but generally those aren't data visualization folks - they may make something pretty, but it'll be hit-and-miss as far as a really great graphic.
If you are a good data person, then you might want to try creating your own infographic first. Use a tool like http://infogr.am/ . The worst case is that you have a sketch you can provide to a graphic designer to guide their final version. Best case, you discover you're an infographics artist at heart
Hope this helps!