That is the question!
I've come across this a lot in the past years of using Sobi2. From what I gather and please do correct me if I'm wrong because there are people that really want to know how to do this...A LOT from what I see on the sobi Forums...but I don't believe it's in working order to be able to limit access to user fields for publishing rights for Sobi. I do believe this will be something that will be a function of SobiPro though. So another amazing feature to look forward to with the new version coming out.
If you want to see more on the topic of how to limit fields here is the forum thread that goes in to a lot of details and ideas of how to go about doing this:
I understand the premise behind doing this...limiting and having different kinds of memberships as an example...bronze, silver and gold. Bronze being only basic information such as name and address and phone number. Then siliver to be more details along with what Bronze would be such as description, website links, hours and maybe a few other details. Then Gold being both the category card and view card of all details.
You want there to be options for the client so people can be comfortable with different pricing points you offer.
However, the way I see it is this...coming from the angle of the user of the directory site and mind you this is strictly my opinion and mine alone. As a user my primary goal when searching for information on anything is to get as much information as possible. I want to find what I'm looking for and I don't want to click on links that don't provide me with the information that I want. Think about how you search Google...and be honest here...don't you get frustrated with the links that only provide you with a name and phone number? I do...I think how is it that with the capabilities of the internet that the internet is providing me the same bit of information as a phone book does in black and white. Only difference is that it's now surrounded with dozens of ads.
When I go in creating a directory I want the listings to be both valuable to the user and the client that is setting it up. So the more information they can provide the better it is all across the board. The more informative your directory is the more likely people will use it, the more people that use it, the more your clients are going to want to use your services seeing how many people go to your site. This is again all my opinion alone and some of it is theory...but I simply do not believe this...that people in todays standards are wanting to look up just a company name and phone number anymore especially when it comes to the internet.
So now you may ask...how do I implement different pricing points to get more clients and not all clients are going to need to use all the areas. First off...if there are businesses that can't use all areas of this kind of listing I have question how they are in business because, they to me, do not have the business structure and marketing tools they need to be a known business. Secondly, if businesses have this opportunity to provide all their information and don't then it is completely their loss...and they will almost for sure loose business to the listing above or below them. Lastly, there are other ways to implement pricing points...
The idea of saving money with the more they buy. As a consumer if I can save a good percentage for paying for the year as oppose to doing lets say 3 months or 6...I'll even though may not need it go for the year. Especially when I feel like I'm saving a hefty percentage like 30-40%. I would sway from doing 1 month increments...there's simply no need for this. I do like the idea of 3-6-1year and not the FOREVER ones...and this is why. If you have an option that is forever that means that listing is going to remain on you site FOREVER and unless you have the time to check and see that all information is valid on a regular basis your site will quickly fill up with BAD INFORMATION. I never understood that kind of setup...yes sounds enticing for the user but so bad for your site. The smaller increments keep the information up to date.
So how do you keep the clients coming back...try making it a solid idea...make the listing affordable and the idea that this is a VERY important marketing tool and is one step away from being a second website or maybe for small business their actual replacement of a website.
To wrap it up...don't make your packages be enticing by the amount of information they provide but by the savings they get for the longevity of their listing!
Good Luck & as always Stay Inspired!