Convincing your manager to allow you to purchase access to Festival of Email should be a simple enough process. Your manager will want you to be able to make use of the opportunities available especially when you help the understand the kind of potential return on a minimal investment.
Many things to different people
As this is an inaugural event many things are yet to be defined. However we suggest the following template of benefits that needs to be customised to your needs. Choose and customise three benefits that match your case:
Networking Opportunities: With the restrictions imposed on movement with the global pandemic these kinds of events have proven to be extremely useful in creating new contacts for learning/sales/partnerships/supplier relationships. In particular I hope to have the opportunity to network with A/B/C who I know is speaking/attending.
At My Pace Training: I will be afforded immediate access to recorded material and training. Of particular interest is Phishing Awareness/DMARC & BIMI Training/Email Threat Training/Complete PsySec essentials/Designing Accessible Emails/Efficient A/B Testing.
Exclusive Offers: as an all access delegate I will be afforded membership of Email Expert Academy which contains deliverability/marketing/technical training materials and certifications from orgs like Entrust, RedSift, Validity with no further payments required.