By leveraging your existing contact network, you can draw repeat business while also creating word-of-mouth advertising from interested and satisfied attendees. You can send automated reminders using the data you already have tailored to any given individual's preferences, so as to reach them in the way that is most convenient for them.
You likely have a lot of existing customer data in many different formats. By inputting it into a contact relationship manager, or CRM, you can then act on it and create a personalized and targeted reminder experience for attendees. Make sure that you have the consent of your customers before scheduling any communications to them.
You can link your CRM data to a decision that will either generate a phone call or SMS message to a given customer, according to their contact preferences. Their preferences can easily be changed within your CRM if they happen to change their mind about how they'd like to be contacted.
By sending an additional reminder to your attendees on the platform of their choice, you will ensure that you have their attention regarding your auction shortly before it begins. A second reminder ensures that your customers don't forget about attending your auction.