Businesses that want to succeed in getting better ranking in search results will need to consider hiring a SEO company to help them with their website. Some businesses will do the work in-house, but it can be more expensive to have someone in-house as they will need benefits as well as pay. Companies that specialize in search engine optimization will often have a better chance of figuring out new tricks of the trade to get better results.
An SEO company needs to be on top of any changes that happen with search engines as they can adversely effect search results. It is easier for them to make changes and see the results when they are working for multiple accounts versus an in-house manager only dealing with their business's optimization. Sometimes a search engine will make some changes that need to be quickly addressed and an experienced SEO company will be able to make sure that everything gets back on track.