1. When users call, if it is a first time caller, ask the user to select his preferences and link his phone number on the website (which is anyway being done in most group buying websites)
2. The next time the user calls, fetch his preferences from the database and play back the deal to him in his preferred language.
3. If necessary, you can connect the caller to the business directly or process payment over the IVR.
The advantages with this approach are:
1. No more spam as callers call to know the deals
2. Play back the deals in multiple languages.
3. Reach more customers.
This can be achieved in 10 lines of code as shown below.
require_once('response.php');// this is kookoo library. You can download it from KooKoo website.
$r= new Response();
if($_REQUEST['event'] == 'NewCall')
//get the phone number of the person who called
//get the deals for the categories chosen by the caller.getDealForCustomer is the function
//which gets details from your database.
//playback the deals and hangup
$r->addPlayText('Your deals are '.$deal);
If you want you can extend the above code to include payment processing, allow a user to modify preferences etc. Since the code and the business logic reside on your server, you can customize it as you see fit.