One of the more unassailable requirements of kosher kiddushin is דעת המקנה, consent/knowledge on the part of the one being acquired as to what’s happening. Traditionally this was so that one couldn’t marry a woman off without her consent, but now, the question lingers: if a woman gets married without knowing that her wedding ceremony includes a kinyan and requires a get to be given by her husband, has she given informed consent?
There’s also a principle of “mekach ta’out” in play, aka agreement under false pretenses.
R. Meir Simchah Feldblum, in an article titled, “Ba’ayot Agunot uMamzerim” in Dine Yisra’el, XIX (5757-5758), argues that, were women aware of the technical nature of their marriage (ie, that receiving a ring equals being acquired in some sense), they would not consent to a halakhic wedding ceremony. He uses this principle as a way of annulling many weddings, in situations in which a woman is left stranded without a get. They didn’t know that they were being bought, therefore it doesn’t “count” as a kosher wedding.
This isn’t a shita (method) for weddings so much as a factor to keep in mind through all of this. Many rabbis fail to mention the kinyan factor to prospective couples as marriage planning begins–for understandable reasons, since the rabbi wants the couple to have a kosher wedding, doesn’t want them (particularly if they’re not very Jewishly engaged) to freak out and refuse to have anything to do with the religion, etc. But said rabbi may be doing them a great disservice, since the status of their eventual marriage, if the bride doesn’t have knowledge of what’s happening, is in question. On the other hand, it’s a handy loophole if there’s concern about ever needing to annul the marriage because a divorce isn’t being granted.