Hi Jerome,
My website allows for anonymous purchases, and we are a dues-paying charity. Using HikaCart, amazingly I can now allow members to purchase their annual dues online. But without some sort of variable field I won't know which member purchased their dues without investigating the buyer's email address. I guess it would be ideal if the shopping cart included any sort of textbox for the buyers to fill in, so that the string appeared in the emails which PayPal sends out to merchants.
PayPal itself allows for a variable field for their PayPal button links, placed onto websites, and I guess this field's string becomes concatenated into the item's description on the PayPal website, as well as printed onto email communications to the merchant.
Regards,
David