I haven't been following SEM quite as closely as I used to, but I had an opportunity yesterday to talk with some savvy folks in the space and thought I'd pass along two companies that piqued my interest.

The first is Efficient Frontier, of Mountain View, CA. I first heard about the company when their funding (Redpoint Venture and Cambrian Ventures) was announced this past summer. The company's technology promises to maximize SEM returns by applying "Wall Street analytics" to your keyword campaigns, managing them as a portfolio rather than individually, ala Bidrank et al. There are a few other players that claim to be doing what Efficient Frontier is doing, but I have it on good advice that EF "has the goods".

The second company is Offermatica, of San Francisco, CA. Offermatica offers a service for something that many top retailers have built internally, use religiously and guard jealously: multi-variate landing page testing and optimization. No matter what you do online, if it involves conversion, you need to be doing multi-variate testing... and if you can't build it, you should take a hard look at these guys. I suspect that Google, Yahoo or MSFT will either build, buy or partner for this technology in the next 12 months; conversion is in their best interests too.

I'll be tying both of these companies into a broader theme... shortly...

(BTW, I have no relationship with either of these companies.)