I have a full V.I.P area on my site, with a general chat lounge, and V.I.P member discussions. The V.I.P's get to decide on major changes to the site, and the rest of the members get to decide on minor changes. We discuss things like T shirt designs, and other items we would like to get done for the site.We also hold V.I.P at home dinners, at a different V.I.P's house each time. So we are a very social bunch of people as well.
I also have another sealed section just for the Ladies on my site. Being based on the automotive side of things, i thought this would be a good little area for the girls to get away from the main stream if they choose to do so. They can also discuss "forbidden" girl topics in there without any sort of snide comments coming from other members. I can not even see in the ladies section, and the two moderators i have for the "Ladies area" are both ladies as well.
I think it gives something for your members to work toward being. Whether it be by post count, or bought membership makes no difference whatsoever. Mine is run two ways. Bought with site upgrades, different user color, user title choice, and other bits, and a OFFICIAL site sticker for their cars. I also give away V.I.P memberships to those members that show not only an interest in the site, but go above and beyond that. It is not something i advertise either, but i always make a thread about it when i give a member that package.Again, gives the rest something to aim for and they can see their efforts will actually be rewarded on my site, not just taken with no credit given to them. Any money taken for V.I.P memberships is also listed in the V.I.P area, and all those members get to decide on what we spend it on, or if we put it into a big free x mas dinner for everyone ( like this year)
Both my V.I.P area, and Ladies section are very active, so it does work in that regards. If you did not have the need i wouldn't bother with it. But why not throw a poll up on your site and actually get your members thoughts on it. You would know straight away then if it is worth doing. Members may be waiting for something like that to happen on your site, but you will never know if you do not ask them.
Everything i do on my site is put before the members for votes BEFORE i do it. Members make a site, and without them we all have nothing, so why not involve them as much as possible..
Sorry for the rant, i just read a lot of negatives on sealed areas, and i know first hand they can and do work.