If you want to build up a following of genuine potential customers, you need to project your personality thru your Twitter and not all talk about your business and your products. Most business Twitter accounts fail because they're nothing but a splurge of sales & marketing dribble and people don't want that.
Post things relevant, but personal, for example a restaurant meal your enjoyed and comment on the furnishings, post / share pictures of inspiring restaurant interiors, etc.
Think about your audience - are they restauranteurs / owners? what would they be interested in? Talk about that.
Gaining ONE real follower because they liked what you Tweet about is worth more than 100+ followers you acquired thru some 'get-followers-quick' scam.