Often around here Kings and Queens or Barons and Baronesses will call up new people who are enjoying their first event. Sometimes they will give small gifts to the people to encourage them to come back.
One King a while back wanted to give tokens that would allow the new people to come to the next event free of charge. The SCA corporate did not like this idea. There seems to be a problem with the SCA to officially give away items of value to some members!
So what can you do?
You can encourage the people you contact on your own. You, if you are financially able to, could invite potential new members to the next event and offer pay for their attendance.
We here in al-Barran, have started to give new tunics to needy new members who have shown enough interest. I met several people up at Battlemoor who were there in the new costumes they were provided with.