Opendoor made over two million offers to curious homeowners in 2021, exponentially more than ever before.

Why it matters: This highlights the growing potential of Opendoor's "top of the funnel" customer appeal -- which is beginning to rival Zillow.

• Opendoor and Zillow are both in the game of attracting consumers and converting them to monetizable customers.

Dig deeper: Of the 2.1 million offers Opendoor made in 2021, it only purchased 1.8 percent, or around 37,000, of those houses.

• Based on the company's numbers, of those 2.1M offers, five percent, or 105k, represented unique "real sellers." Of those, 35 percent sold to Opendoor.
  
  

• That purchase rate has decreased over time as Opendoor has ramped up the number of offers it makes while automating the offer process.

A low purchase rate does raise questions of product/market fit.

• Based on the total offers sent out, a very small number of consumers are deciding to sell their home to Opendoor.
  
  

• But of "serious sellers," one in three ain't bad.

Yes, but: Hundreds of thousands of consumers are actively deciding to visit Opendoor to request an offer.

• Even if Opendoor doesn't buy the house, the company still touches a homeowner during their home buying/selling journey, creating an opportunity to cross-sell adjacent services (brokerage, mortgage, leads to agents).
  
  

• And, as we'll see below, overall customer conversion is on par with Zillow.

Zillow's powerful top of the funnel customer acquisition tool is its web site, which generated an estimated 21M leads in 2021.

• Of those, 1.4M were "real buyers" and 26 percent of them (360k) ended up transacting with a Zillow Premier Agent.
  
  

• That results in an overall conversion rate of 1.7 percent, exceedingly similar to Opendoor's 1.8 percent.

Zillow's dominance at the top and bottom of the funnel is clear: 10x larger than Opendoor.

• But surprisingly, Zillow, the decades-old industry heavyweight, is only 10x larger than Opendoor, which has made notable gains.
  
  

• There are variations in conversion rates throughout the funnel, but overall efficacy is nearly identical.

Remember: Zillow is optimized around home buyers, while Opendoor is optimized around home sellers.

The bottom line: With similar conversion rates, neither company has built a better mousetrap, but Zillow's mousetrap is exponentially larger.

• In terms of customer reach and the sheer quantity of leads generated, Zillow has a huge advantage.
  
  

• But with its ongoing national expansion, heavy advertising investment, and automation of the offer process, Opendoor is making significant gains -- and the growing power of its top of the funnel customer acquisition can't be ignored.

A note on data: The last time Zillow reported the number of leads generated annually was 17M in 2016. My assumption of 21M leads in 2021 is a well-informed estimate.