Getting your message out to a big group of people is expensive. It takes the collaboration of many different media platforms. Social, Billboards, Radio and TV. Don't try and compete on the mass scale as the big chains will always dominate.
Your restaurant needs focus, connection and engagement. You need to find the individuals who love your restaurant and encourage them to spread the word.
You need superfans. You don't need 50,000 followers and 10,000 email addresses. You need to find a group of people who love your restaurant and love hearing from you. This might be as few as 100 people.
100 people who are engaged and you communicate with frequently will always be better than a list of 10,000 people on a list that you send a newsletter to once a month.