A new analysis of portals shows how OnTheMarket has eaten into Zoopla's agency membership - but also claims the new site has a struggle to achieve its second portal' objective.
The analysis - by Home.co.uk - has looked at a range of portals' agency memberships on two dates, December 15 2014 and March 10 2015.
Home says that with 4,927 agents signed up by March 10, OTM is fifth behind Rightmove, Zoopla, Primelocation and Mouseprice, and only just ahead of sixth-placed Nethouseprices.
The agent figure from Home is actually higher than the most recent figure released publicly by OnTheMarket itself, which last week said it had 4,800 member agents.
Home's analysis also shows that the day after OnTheMarket's launch on January 26, Zoopla was used by 10,712 agency offices. But by March 10 this had fallen to 9,072.
Meanwhile, over the same period, the number of agents using Rightmove barely changed, with its January 27 tally of 12,850 falling by just 138 to 12,712 by March 10.
Home says that there is evidence that the exodus from Zoopla is tapering off, however. On March 10, there were 6,933 agents continuing to use both Zoopla and Rightmove, a tally that has fallen by just 108 since February 25, compared with a much larger fall of 1,142 between January 27 and February 2.
Home also claims that online traffic figures from the Alexa Traffic Rank - an internet analytics firm owned by Amazon - show that OTM was in 38,233rd place worldwide whereas Rightmove was ranked 859, Zoopla 1,920 and Primelocation 11,741.
However, OnTheMarket has strongly refuted the traffic figures produced by Home, calling them inaccurate and misleading.
OTM chief executive Ian Springett told Estate Agent Today over the weekend that: If Alexa is used as a measure, it is its UK rankings which are most relevant. After only eight weeks since its launch, OnTheMarket.com is already ranked at 604, placing it among the country's most visited websites.
He goes on to say that Home.co.uk itself is ranked only at 2,789 - and that is after more than 18 years in existence.
Our progress will continue as we add more members and properties, extend consumer awareness as our multi-million pound advertising campaign continues and begin to gain high rankings on major search engines. Our entry to the portals market increases competition. No agent or consumer has any less choice than they had before says Springett.