In South Africa, I was reluctant to offer anything other than cash. Business was slow but there was never a cash flow problem (other than not enough).
I quickly learned that cash was a problem. Especially when the customer only knows the price one the techy has measured up. Internet banking was the only solution. Last financial year I wrote of about R2000.00 (divide by 15). This year, so far I have 2 customers that have not paid and probably will never.
Having said this you need to put in place the necessary processes to follow up with your custy (out of sight, out of mind - they forget).
Business is booming but I sit with outstanding invoices to the value of R40,000.00 admittedly most of which is corporate.
Internet banking is a must. It also gives you great marketing advantages as you can get home phone, cell phone, e-Mail and any other stuff you may need for your referral programs
Jeremy