Questions about Authorize.net

[pagypsy]

Does the SIM version require SSL? I don't really understand the differences between the AIM & SIM version, and which is "better" to use, and why.

[DrByte]

AIM requires SSL.
SIM in "offsite" mode does not require SSL, but should be avoided IMO.

If your question is really "can I get away without an SSL certificate", the right answer is: are you collecting any information about your customers? If so then yes, you need an SSL certificate. And, since the answer *is* yes, then ... yes, you should get an SSL certificate.
They're not as expensive as they used to be, and are a worthwhile investment.