You have to look at your website, blog, social media presence and client portfolio. Browse through your customer list and go to your websites to understand the quality of the work they provide. In addition, there may be a good idea to hire an agency with previous industry experience. For example, if you are an e-commerce profession, it will always be good to hire the digital marketing agency.
The sole SEO cannot do much for your business, but when marketing with content marketing, social media marketing, email marketing, mobile marketing and PPAC marketing, it can help businesses reach the peak of online success.