I have actually put up a site for nude models in Portland, OR (where I work). Here it is:
http://www.modelspdx.com
It gives models (especially newbies) good advice for staying out of trouble and not seeming like an idiot when they work with photographers. Here is what I say there about test shoots:
(begin quote)
One area where photographers may try to scam models and yet it may also be legit is in the area of the "test shoot." The purpose of a test shoot should be to see how you look in photos (this "photogenic" thing is real!). However, a test shoot should be just that, a few shots, not two or three unpaid hours of your time. Test shoots are typically unpaid and while the thought of posing for free may make you uneasy or even angry, it's the way a lot of photographers operate. We would suggest limiting a test shoot to no more than 10 or 15 minutes and no more than 36 or so shots (one roll of film).
Aside from assessing how you look in photos, another reason for a test shoot may be that the photographer wants to see how well you follow directions, whether you can self-direct (a big plus in a model), whether you have any sensitivities (not liking to display yourself in certain ways, or not liking to show certain parts of the body, etc.). He may decide not to work with you after the test shoot, just as you can decide not to work with him anytime you like.
One last reason for a test shoot is to get some basic shots to sell you to the photographer's clients. Obviously, this could benefit you.
If you are doing a supposed "test shoot," it isn't unreasonable to ask the photographer to add a "no commercial use" clause to the release, or to ask him why he needs a release at all, since the purpose of the release is to give the photographer permission to publish the photos! A line something like "The result of this session will not be sold for commercial gain" could be added by hand at the bottom of the release form but above the signature line. Be sure that both you and the photographer initial this change, or the change may be worthless.
Is the photographer scamming you or not? Well, people are surprisingly consistent. Ask to talk to some of his other models. If they have never felt screwed over, you probably won't be screwed over, either. If he's hesitant to supply references, be careful.
(end quote)
We currently are plagued in Portland with assholes who finish up supposed stills shoots with offers for the girls to do "point of view" (where the cameraman gets sex, usually a BJ, while holding the camera on the girl). These guys invariably get reputations with the experienced girls as sleazes, but there are always new girls coming into the field. I think if a guy intends to try to get a girl to do hardcore, she should know that going in, not find out at the end of a stills shoot. I won't list photographers in the aforementioned site who do "participatory" hardcore unless they mention it in their listing. If he's soliciting models for blow jobs, the girls should know that going in.
As to the quality of photos being offered by the various vendors, I frequently run into people who don't understand that "quality" for the webmaster is measured by how well the work functions in terms of garnering and retaining members, how it fits in with the site's style, and so on. Many people are mesmerized by a style they personally like, or which may involve technical difficulty or expensive gear, or trips to exotic locations, and this is their standard. Well, they are entitled to like what they like, but as a business standard, it's nuts.
I know what I like (and it's not Playboy or Penthouse style, FYI), and for myself I measure what I see against what I like, but I also realize that what I like and what I make will not work for every site out there.
The only rational standard is one known to any businessmen: "if it works to maximize profits, it works." Photography suitable for a "babe" site simply isn't appropriate for a "reality" site.