Monday was a good day to work at AdMeld. The Real-Time Bidding (RTB) advertising optimization technology company announced it has doubled the size of its client base since June, with key additions coming from AccuWeather.com, Answers.com, Billboard.com, Daily Kos, Hearst Television, New York Post and Time Out New York. The company has reached 130 publishers in its client list and access to more than 160 million unique users in the US and 275 million unique users worldwide, according to Quantcast.

AdMeld CEO Michael Barrett says the company’s success is a sign that RTB is a key revenue optimizer, and also a sign that ad technology is still an urgent need for publishers. “Things aren’t getting a lot easier out there for publishers,” he said. “They don’t sell direct to a lot of their brands, and those brands certainly have a lot of choices as to where they can spend their money. Monetizing inventory is all but impossible unless you have the technology to do it effectively.”

Barrett also believes AdMeld’s current positioning as a publisher advocate had helped the company’s success. The company works exclusively with publisher’s rather than agencies or brands to design RTB ad campaigns. The technology it is built on creates dynamically optimized ad tags to select the most relevant mix of ads across hundreds of ad networks and exchanges. The company also provides a range of services that it claims will eliminate the complexities of working with multiple ad networks, such as consolidated performance reports and payments. Lastly, AdMeld protects publishers' brands by enforcing ad block lists with FireMeld.

Up next: expansion. Barrett says his current client list is asking how they extend the solution into global markets and into mobile advertising. “I don’t know we’re a mirror of some decreasing amount of content online,” he says. “We are emblematic of the key marketing force that’s still at play, at that dynamic is a large supply of inventory trying to attract a smaller supply of ad dollars. We have been successful at solving that for our clients.”