Influencer marketing is by far the fastest growing marketing channel this year, and it doesn't show any signs of slowing down. A 2015 poll by eMarketer showed that 84 percent of marketing professionals planned to launch at least one influencer marketing campaign within the next year. But it's not as simple as it may sound. Most companies have found that they lack the resources or know-how to launch an effective campaign on their own.

According to Reuters, 47 percent of online customers use ad-block technology, and TrackMaven found that, while 78 percent of brands increased their content output during the last two years, average content engagement decreased by 60 percent. This illustrates that effective engagement requires more than just creating content and targeting ads.

Influencer marketing campaigns target potential customers inside of news feeds, bypassing adblockers and utilizing word-of-mouth to gain trust. According to Variety, eight of the 10 most approachable, authentic, and influential people for teen audiences are YouTube stars.

Put simply, if your brand wants to stay relevant, you need to launch an influencer marketing campaign and get the help you need to succeed. You can start with this list of influencer marketing companies that are already assisting brands by educating their audiences and earning their trust.

1. The Blu Market

The Blu Market is boy band star Kevin Jonas's passion project and is quickly becoming an incredibly successful influencer marketing firm. Leveraging his own influence as a star, Jonas and co-CEO Steven Forkosh recently created a strategic partnership with We Heart It, an image-centric social-media platform popular among young Millennial women. The partnership focuses on promoting We Heart It premium content to new audiences through influencer networks. Blu Market has a network of more than 9,000 influencers with a reach of more than 300 million followers and works with brands to drive mobile app installations and measure everything through tracking links.

2. BoostInsider

Chasing influencers can be very time consuming for brands, and influencers don't respond to spamming or cold calls. Brands look to BoostInsider to ease the difficulty of trying to find the right influencers. BoostInsider works with a top-down strategy, calling on many of the largest influencers who don't want to name their price on a marketplace, and then filling in a comprehensive second tier of influencers who boost that signal. BoostInsider's goal is to be a full-service agency with the technological feel of a marketplace. BoostInsider's streamlined strategy and influencer connections make them a must for big brands.

3. NeoReach

NeoReach is a self-service platform designed for Fortune 1000 brands and their agencies. Brands can do everything themselves or they can hire an influencer expert to manage their campaigns. Boasting a base of over 10,000 influencers, NeoReach offers an individualized package model that allows for pre-approval and a quick start. However, they also include a personal touch and outreach services for influencers you may want to target but don't know how to approach.

4. FameBit

The FameBit (recently bought by Google) marketplace is simple and easy, with a drop-down menu including pricing options from $100 to $10,000, giving you a way to work within your budget but still leverage the benefits of influencer marketing. Influencers can then bid on the campaign, making it one of the easiest online influencer strategies. Though it can be impersonal at times, FameBit is very straightforward and could be a good entry point for larger brands that can afford FameBit's 20 percent service fee.

5. Glispa

Glispa is a performance-based mobile marketing company that brings a global perspective to influencer marketing. Located in Berlin, Beijing, San Francisco, Bangalore, São Paulo, and Tel Aviv, it offers mobile marketing, social-media marketing, search engine marketing, media planning, and buying. Glispa's proprietary technology provides many options for accurate metrics, fraud and bot deterrents, and more.

6. Grapevine

Grapevine is a trusted self-service marketplace that boasts impressive click-through rates and sales conversions, as well as proprietary reviews from other marketers to help brands make confident decisions. Though they only work with YouTubers, Grapevine is a simple, easy-to-use format that deals in paid sponsorships and packages. Brands have dedicated account managers to assist with the process, helping to facilitate and maximize the results.

7. BrandBacker

Founded in 2001, BrandBacker has a network of over 10,000 influencers who are paid upfront with discounts or free samples, depending on the campaign. Brands using the "Content Showcase" feature can collect all content created about their brand Web-wide, which can then be curated and organized to leverage everything on their website and across media channels. Brands can publish this curated content goldmine straight to their website.

8. Niche

Co-founded by Huffington Post's first social-media manager and journalistic phenom, Rob Fishman, and boasting Vine star Cody Johns as creative director, Niche has quite the pedigree. Beginning with Vine, Niche now serves all social-media platforms. Unlike other influencer platforms, Niche has an aggregate dashboard where influencers display all of their branded content alongside full analytics tracking. This feature allows brands to see which influencers are generating the most success with engagements.

Selecting an Influencer Marketing Partner

When trying to decide which influencer marketing company to select from the list, just remember that certain agencies may work better for your brand than others. If your business has little knowledge of influencer marketing, one of the easier sites, such as FameBit, might work best.

If your brand has the budget and knowledge to do much more, you might prefer BoostInsider to maximize the leverage you can create. Take your time, research each one, and see which influencer marketing company aligns with your goals, budget, and experience.