I used POSPizza in 4 of my shops. It is great for a lot of things, especially setting up a POS on a budget. The best feature it has is the ability to download the customer database into a CSV file that you can play with in excel. You can tweak the numbers and the order times/dates to really increase the effectiveness of your marketing.
My best response rate for a monthly mailer of 2000 post cards was 26%. That targeted new customers, and 30-60-90 day new customers. To give you an idea of what that meant:
Example of a May mailer:
Thank you post cards to all new customers who ordered in April
$3 off to all customers who ordered in March, but not april
$5 off to all customers who ordered in Feb, but not March or April
$7-9 off for customers whose last order was in January (ie 90 days without an order)
Twice in many years of doing it, I broke down the specials further into big combos and small deals. By getting the customers average order amount, you can see if they traditionally order a lot of food, or a single medium pizza. It did increase my sales, but it took a lot more time to get that far into managing the database.
When I set up POSPizza the first time, I spent $50 on hardware. At the time, I had more time than money (and sense). Going with junk is an easy way to spend less money, but getting it to work and dealing with breakdowns sucks time. On the flip side, you do not need the top of the line machine. The $150 refurbished machines I found on Amazon are perfect. Even better with a $50 RAM upgrade to make them run faster. A POS does not tax the system. I paid for the license and the hardware with the first direct mailer I sent out.
The support at POSPizza is great as well. 24/7 Phone support is useless in most cases. If you PC breaks, you are screwed anyway. In 11 years of using POSPizza, I had one software problem with a corrupt database. I did the database maintenance from the manager screen, and was back up and running in a few minutes.