I have a couple of issues with this.
I'm not sure that making an URL mandatory is great. Not everyone has their own website, and for those who don't... why must they then pay for ads on LL, etc? Or would you be OK with a link to an ad on another board, or another advertising service that isn't associated with you guys? That satisfies the requirement above, but I suspect it's probably not what you're trying to achieve. And in any case... the idea that an ad has to link to another ad seems kinda contradictory; an ad should be self-contained :)
Why is a phone number required? This will probably be a deal-breaker for quite a few independent providers who prefer initial contact and screening to be done by email, and don't hand out their number to anyone until they have a confirmed appointment. You've broken their screening model with this requirement, and that will probably just drive them away.
That's... OK, but I'm not sure that it's great to insist that ads for online services *must* be there. Many providers usually/always post in just one forum, and people who know where they're based will look for them there. I see no particular reason to effectively ban them from advertising in their usual spot (which is what this does), especially given how tough things are for them right now. Could you allow both?