I have yet to hear of or meet or see a single post here of someone who lost a booking with AirBnb over the registration issue.
Not Paris and not the 13-digit registration process they have, but just had drinks the other night with my friends who were exceedingly happy that they, and other long-term rental tenants in the building where they live, approached the landlord about another tenant who was frequently listing his apartment on Airbnb. Although it started off slowly and was only a once in awhile thing and everyone pretty much looked the other way, it became more and more frequent to the point my friends and other long-term tenants were starting to see an endless stream of strangers coming through each week. Although the Airbnb guests weren't creating noise disturbances (although several in the past had forgotten the key to the outside door off the street and stood on the front steps pressing everyone's doorbells until someone buzzed them in), they were doing stuff like dropping trash in the trash room and not placing it down the chute and smoking on the balcony which started pissing off the neighbors. According to my friends, the tenants decided to take action once they saw this guy had his place booked solid on Airbnb right up through early October.
The landlord, getting word of what was going on, cited the lease clause which was very clearly written stating no tenants were to sublet or lease out their apartment - so the concept of Airbnb was totally against the landlord's rules. The Airbnb listing just came down and I'd venture a guess that there are some unsuspecting people who had a reservation that will now need to find another place.
The end result of what my friends told me is not surprising to me at all. Having lived in many popular large cities across the U.S. that are on the average tourist's radar, I have seen more than half of my former apartment buildings listed on Airbnb (I can tell from the photos and description) and I've known that all of them are illegal because as a long-term tenant, I read and signed a lease agreement with those landlords that very clearly prohibited me from doing something like Airbnb.
I live in a city where there is a lack of affordable rental units in general for those of us who call this city home on a full-time basis, and while Airbnb does exacerbate the situation further, I am not here to lecture anyone on whether they should or shouldn't use it; however, don't act like just because you've only had (or heard about) positive experiences with it, it doesn't mean that there aren't some people who don't get completely screwed over when a wrench is thrown in their planning late in the game. Hell, I've flopped in Airbnb and VRBO rentals that my friends have booked in other locations from time to time, but generally when it's up to me to find myself someplace to stay, I tend to stick to hotels, hostels (which have private rooms, family rooms and offer access to all the same things you "need" from an apartment rental - like ability to cook a meal, store food in a fridge, do laundry, or stretch out in bigger rooms that don't have a bed plopped in the center), and apart'hotels like Citadines (which has locations in Paris).
Stephanie still has not given an indication of what she's looking to spend for a nightly rate or how many bedrooms she requires in a rental, so makes it tough to give her viable options that will meet her parameters. But she can go online and run a simple search using that same input on Booking.com and select apartments to see what comes up, or Airbnb or VRBO - then make an inquiry as to where the unit is located so she can cross check it against Google maps and see if said apartment is sitting directly on top of a nightclub.