For a different approach try blue tooth and facebook advertising, more below.
You are off course correct, you need to get the numbers and telephone numbers first. You also have to be carefull of being identified as a spammer. The law in the uk is that you are not allowed to send unsolicited emails to individuals, even if you giving away free food.
If you do decide to send emails messages you will need software to send them, that is if you don’t want to do copy paste, try sendblaster just google it. You should also offer a means of unsubribing, you can do this it sendblaster or you can add a line “to remove please send a blank email to remove@???.com”. If your website gets seen as a spammer by google, good night your website sales. You must also offer a means of stopping text messages. Never used this but the are a lot of pay as you go mass messaging systems out there, about £0.09 a go.
Bluetooth. There quite a bit of software out there now, that you set up bluetooth at your store, anyone who walks pasts with an open Bluetooth connection (range of 100m) you can send them a message automatically, after the cost of the software £100 ish, the message is free, being used a lot in night clubs.
Try also Facebook advertising. You can set this up so that your ad will only show to facebookers who live within your encatchment area, on a Friday and Saturday night, to 20-35 year olds, or what ever you decide.
On all these methods you will need a website for people to go to and see your offerings. Don’t skimp on your website, there is no point in spending time and money in sending people to a website that is poor. It’s like putting big engines on a plane that cant fly, it will just crash quicker. Make sure your website works before you spend money in promoting it.
Think about google ad words as well. You can also make adds local, can prove to be expensive though if you set them up wrong, buy a download PDF by Perry Marshall google ad words course, $100, good investment if your serious about ad words.
Also install google analytics on your website so you can see what works and what does not.
Hope that helps
Mark