Initially I was concerned with the security of PayPal.
Indeed my wife is a CPA, and has attended a few very informative
professional development classes where the instructor described various
forms of credit card fraud. While many of these problems may remain
for many entities, I have never experienced a problem with PayPal. I
have channeled approximately $100k of funds through PayPal in the past few
years, and PayPal has been flawless. Their security and accounting