I've tested out Twitter Ads recently to promote a business account, but it didn't work out very well in getting lots of followers. Also the kinds of followers it got from that campaign were other twitter users who were trying to get more followers as well. AKA, people already following thousands of other accounts.
So what do you guys do? Heres a few things I do.
Search for 4square checkins: A lot of times people check in to a business using four square, but never really know the business has a twitter account. So searching for that checkin, and replying to them with a simple comment or fllowing them alerts them to the account.
search for local tweets in your area: using the "near:90210" or "near:NYC within:15mi" twitter search operator to find local tweeters and interacting with them. Especially good if they tweet or ask about things your business sells.
Search for tweets about competitor: Searching for mentions of a rival business that is nearby... Interacting with those tweeters can start a dialogue with potential customers who will follow you.
Following users who follow other business nearby: Finding another local business nearby, and checking their followers to follow or interact those users.
searching hashtags from your area: Whether a city hashtag, or lcal hashtags used in your area that you can monitor for tweeters to interact with.
I'm probably missing a couple other methods I can't remember now.
But i;m curious to find out what other people do. What are your best methods to get REAL local followers quickly?