OnTheMarket now has listing agreements with over 8,000 agent branches.
Hitting the number means that it has now recruited 2,500 more offices since it floated on the stock market on February 9.
The recruitment rate, at over 800 per month, compares with the 100-plus returnees to Zoopla per month, which ZPG announced last week.
The increase in OTM agents represents growth of more than 45% in just over three months.
The first 1,000 new branches were announced on March 14, with the 7,500 mark revealed on May 2.
CEO Ian Springett said: “We are extremely pleased to be continuing to exceed our own expectations and to have reached this latest milestone of 8,000 offices so soon after announcing 7,500 offices.
“In sustaining this pace of expansion, we are very strongly encouraged by the growing agent support and feedback to our proposition.
“We remain committed to creating an agent-backed, full-scale challenger portal that injects some much-needed competition into the property portals landscape by disrupting what has for too long been effectively a cosy duopoly.”
Springett has stressed the importance of building scale in a recent interview with Directors Talk, when he set out his stall to new investors.
In it, he said: “We will be giving updates to the market from time to time about our progress in building the number of agent offices we’re listing, and that’s a pretty key indicator of our progress in building the network to full scale.
“The faster that we can reach that scale, and the same scale as our competitors, the sooner we can begin investing more in marketing to help deliver more enquiries to them, and of course, the sooner consumers will find a comprehensive stock of property with onthemarket.com.
“We’ll also update on our visit traffic. Investors should look for steady growth over the coming months ahead of our fuller marketing push later in the year, once the agent network has been built up.
“They’ll certainly see some brand building activity from us soon and they can also look for our logo in increasing numbers of estate agent windows.
“That is one of the obligations that agents take on when they join us and that is to promote us through their own means, in their office windows, on their websites, on their property particulars and other advertising.
“Of course, investors can just come to the portal, try the portal out, see how it compares with the others and obviously, if they are searching in their local area, they should see more and more agents listing with us over the coming months.”
In the same interview, Springett said that the field sales force has already doubled to 32, and will double again by summer, with more numbers added as the year goes on.