Blekko sought out from the start to become the “third search engine” behind Google and Bing (Yahoo, for all intents and purposes counted as Bing, since Bing powers Yahoo Search). Google and Bing serve search ads to monetize their efforts.

Now, the “third search engine” is testing ads, according to a report from MediaPost. These ads, however, are coming from Google and Bing – AdSense and Microsoft’s counterpart. Laurie Sullivan reports:

Visitors who visit the search engine, however, probably will not see a search ad based on their query. Few are linked to slashtags, which helps to curate content, according to Rich Skrenta, Blekko founder and CEO.

“We’re still ironing out the kinks,” Skrenta said. The company will measure success based on RPMs — page revenue per 1000 ad units.

Meanwhile, Blekko’s peer (in terms of alternative search engines), DuckDuckGo, announced that it saw over a million searches in one day for the first time. (hat tip: SearchEngineLand)

Both alternative search engines announced new funding last fall. Blekko announced a $30 million investment from a mix of investors in September. In October, DuckDuckGo announced its first round of funding (the amount was not disclosed).