Photo: The Motley Fool

Zillow (NASDAQ:ZG) has had an interesting summer, highlighted by July's announcement that it would be buying smaller rival Trulia (UNKNOWN:TRLA.DL) in a $3.5 billion deal.

As fate would have it, Zillow hosted its second-quarter earnings call earlier this month, giving it an opportunity to discuss the deal, its recent performance, and the future of real estate portals.

It was another blowout performance, giving Zillow another opportunity to boast. Let's go over a few of the interesting morsels out of Zillow's conference call in early August. 

Zillow's hitting on all cylinders

We are executing well on our three strategic priorities of growing our audience, growing our Premier Agent business, and growing our advancing marketplaces. 

It's clear that Zillow's rocking in terms of growing its audience. It attracted 81.1 million average monthly unique users during the quarter, 27 million users ahead of the prior year. After the quarter ended, Zillow drew a record 89 million visitors across its site and mobile app in July. Mobile's a big part of Zillow's reach these days accounting for two-thirds of its usage. A whopping 500 million homes were viewed on Zillow from a mobile device last month.

Premier Agent -- the real estate professionals that pay up for greater visibility and enhanced access to the portal's features -- are on the rise. Booking volume during the quarter more than doubled over the past year, up a head-turning 40% sequentially. In fact, Premier Agent revenue growth has accelerated in each of the past three quarters.

The third strategic priority is growing its advancing marketplaces. Its Zillow Mortgages marketplace took a step back, but it actually held up better than the overall mortgage market as loan applications, and particularly refis, have been sliding. The weakness in drumming up mortgage leads was more than offset by growth in Zillow Rentals, HotPads, and StreetEasy. 

Things still don't "ad" up

We have been reinvesting much of the upside into brand advertising. For the full year 2014, we now expect $75 million in advertising spend versus our initial outlook of $65 million, with about half of the $10 million increase yet to be spent in the back half of the year.

This is actually a pretty big admission. Some have argued that the combination of Trulia and Zillow will make it easier for the combined company to relax its marketing budget. It will no longer have to spend big ad dollars to set one apart from the other, often at the other's expense. 

The deal won't close until 2015, but it's still odd to see Zillow gearing up to spend more than less when it knows that it has Trulia in its back pocket. 

Things continue to get even better than Zillow's own upbeat outlook 

Due to our strong second quarter results and record bookings, we are increasing our total revenue outlook from $306 million to $322 million at the midpoint of the range for 2014 and also increasing our EBITDA outlook from $49 million to $53 million at the midpoint.

Zillow boosting its outlook after yet another blowout quarter isn't a surprise. One thing worth adding to this heartier guidance is that this has nothing to do with July's announcement of the upcoming Trulia acquisition. As pointed out earlier, Zillow doesn't expect that particular deal to close until next year. A strong quarter and a record July are clearly helping. 

Realtors are leaning more on Zillow for leads

The increase in ARPA (average revenue per agent) has been almost entirely driven by volume. We went through the numbers with a fine-tooth comb, and it was effectively all volume.

A big driver at Zillow is that real estate pros continue to spend more to get noticed on Zillow. ARPA clocked in at a record $320 for the quarter, 20% ahead of where it was a year earlier. Same agent ARPA for Premier Agents was up an even more impressive 62%.

Zillow isn't charging them more for their leads. It points out that local ad prices have held fairly steady in recent quarters. The difference here is that Zillow's volume of impressions continues to outpace agent growth. Real estate brokers and agents clearly aren't complaining about the extra leads.

Zillow plays nice with social media as a corporate communications platform 

I'll do a Twitter question and then back to the call in a moment.

Brian Bolan -- @bbolan1 -- asks, "Are you seeing any real estate areas that are becoming a little bubblicious?"

Zillow became the first publicly traded company to invite analysts and investors to ask conference call questions via Twitter a little over a year ago, and clearly it's still doing exactly that. It still leans mostly on Twitter questions asked by analysts and in this case a former research analyst, but it's great to see this continuing at Zillow. The democratization of Twitter is a neat thing, even if it would be great if more of the questions presented during its latest earnings call came from regular retail investors. 

And, just so you're not left hanging on the answer to the actual question, San Francisco and New York City were singled out as two markets that seem to show no signs of cooling down.