A Digital Marketing Retainer is an agreement for me to provide a series of wide ranging services to your business, for a certain amount of days per month, every month.
Digital Marketing is not a fixed service like setting up a Google Ads account - although the 'levers' are often similar, your competition is different for each keyword and the work changes accordingly. Read this blog article for more information on Retainer Agreements, and this blog on what services can be included in a Retainer Agreement. You can also understand more in What is Digital Marketing?
Order by days (one, two, five or seven) or multiples of each (3x one day) PER MONTH. If you're not sure - then why not book a Free Consultation to discuss your needs.
Further reading: https://www.ecommerceconsultant.org.uk/blog/digital-marketing-retainer-agreement-length
Further reading: https://www.ecommerceconsultant.org.uk/blog/hiring-an-seo-expert-on-a-retainer