I agree with some comments and disagree with others. .pro would never have worked if registrations had been restricted to the profession of the registrant. That would have been an even more suicidal restriction than accountants, doctors, lawyers and engineers in France, UK, US and Canada.
Not falling into the initial RegistryPro category didn't stop plumbers regging plumbing related .pros via Encirca but did they register and develop plumbing .pro websites? No they didn't. I regged Plumb.pro yesterday and plumbers have had 4 years to register it. I also hold Plumbing.pro and that was dropped in 2007.
Making professionally qualified people stick to their professions would have reduced the keywords available to register by 95%. RegistryPro have been losing money for 4 years with 100% of keywords available and Encirca regging them by proxy for anybody who wanted one. If they didn't have the support of their parent company Hostway, they would have gone bust.
I agree that the remaining .pro restrictions should be dropped. No domain extension can work with restrictions, they strangle the life out of innovation and development, discourage registrar take up, and put off potential registrants. It's hard enough for an alternative extension to make headway with $1 reg fees, no restrictions, and being offered for sale on the main domain panel of every registrars. .info has 5m registrations but disproportionately few high quality sites.
.pro will never gain traction with restrictions that eliminate 90% of potential registrants, reg fees that are still 3-4 fold higher than other gTLD's, and only a handful of registrars responsible for 7.5% of total domains registered offering it. RegistryPro should got to back to ICANN and tell them they still can't cover their costs or market .pro with the current restrictions.
On the plus side .pro is still the most brandable, credible and sweet sounding domain extension after .com. It's not as heavily regged or as speculatively valuable as .info, .biz, and .mobi but it makes them look harsh, artificial and ugly.
Somebody said "many more keywords" don't work with .pro. I don't really agree with that. Virtually all keywords work with .pro, that's one of its biggest advantages. There are 15,000 trademarks in the US trademark registry with the word Pro in and they are across the board. Here's a snapshot of some of my pros, each one a different .pro "type"
Surf.pro (sport .pro)
Pool.pro (hobby.pro)
Gadget.pro (tech .pro)
Total.pro (phrase .pro)
Puzzle.pro (knack to it .pro)
Expert.pro (how to .pro)
Marine.pro (industry category .pro)
Quick.pro (brandable .pro conveying service attribute)
Aqua.pro (brandable .pro conveying product type)
Staff.pro (employment .pro)
France.pro (geo .pro)
Mobile.pro (type of professional .pro)
Office.pro (professional working environment .pro)
Salary.pro (professional word .pro)
Diamond.pro (luxury item .pro)
Surgeon.pro (profession .pro)
Audit.pro (professional service .pro)
Talent.pro (professional attribute .pro)
Boat.pro (product .pro)
Cookware.pro (product with premium professional version .pro)
Tutor.pro (service with premium professional version .pro)
Guitar.pro (skill .pro)
Training.pro (becoming a professional .pro)
Cargo.pro (rhyming .pro)
Prom.pro (Pro followed by Pro .pro)
Then you can combine .pro types;
Piano.pro (rhyming and skill .pro)
Studio.pro (rhyming and professional environment .pro)
Projector.pro (Pro followed by Pro, Product, luxury item, tech)
Expo.pro (rhyming and professional word)
Promo.pro (Pro followed by Pro, rhyming, and brandable)
.pro is the most beautiful, versatile, brandable, commercial and credible alternative extension. The only problem is the registry is run by people who don't understand how to develop an alternative extension and so it languishes in the shadow of other gTLD's shackled by restrictions, high reg fees, no marketing, and only a few registrars offering it.
My hope is that Hostway get fed up losing money and sell RegistryPro to Afilias or Verisign in return for all restrictions being removed by ICANN. Either that or they hire somebody who understands the domain industry and has a track record developing alternative extensions.