HTA learned from the mistakes of others, and tried something different. Its degree of success is debatable, but it certainly is different -- met THAT goal!
If they had converted the untraded shares to traded shares ALL AT ONCE, there would have been tremendous selling pressure from those of the I-don't-care-what-the-price-is, get-me-out-immediately mindset. (That had an a horrid impact on DCT when they went public.)
So, they took all the unlisted shares, and converted them:
* 25% to A shares
* 25% to B-1 shares
* 25% to B-2, and 25% to B-3 shares.
The total number of shares is absolutely unchanged from pre-listing to post. If you had 1000 shares before listing, you still had 1000 shares afterward -- but only 250 of them were tradable on day one.
Every six months, another batch ("tranche") of B-n shares converts to A shares, which, again, does not change the total number of shares out there or the number of shares you hold.
I think it has worked out well for them. Having been forced to hold on to most of our shares for a while, we're now at the point, IMHO, where "who wants to sell something that's up by 35% and still rising?" is the dominant attitude.
All share classes pay the same dividend, too.
It may be important to note that this is NOT the same methodology as Inland Western / RPAI used when they went public. Similar, in that they went with four share classes; different in the way they introduced them.