In April, Google launched a pop-up, temporary marketplace for companies to sell patents, with Google being the sole buyer. Today, the search and mobile giant is expanding that marketplace in the other direction: Google has started a program for startups to buy up to two non-organic patent families off Google. It is tying the offer into a requirement to join the LOT Network, a cross-company licensing push (others in the group include Dropbox, SAP and Canon) aimed at driving down the number of patent trolling suits.

If you are interested, you should get in touch quickly. Initially, this will only be open to the first 50 eligible startups.

And what makes you eligible? There are a few caveats and requirements for startups to qualify to buy Google’s patents. First, a company’s 2014 revenues had to be between $50,000 and $200 million.

Then, Google will not let you pick what you would like to buy. The company says that after you apply, if you meet the revenue requirement, it will send through to you, within 30 days, a list of three to five families of patents, and you can select two of them to purchase. “Google will retain a broad, nonexclusive license to all divested assets,” the company notes.

Interestingly, as part of your application process, even if you don’t end up buying anything, Google says it will give your startup partial access to its own database of patents — presumably covering only non-organic patents.

And you also have to agree to join the LOT Network for two years before you can buy any patents.

The LOT Network is essentially like a patent owners’ club. Members get free licenses to use patents whenever one of those patents is commercially licensed to a non-member. There are some 325,000 patent assets in the LOT database already, and the idea here is for Google to help the group get stronger, as a way of warding off patent trolls.

While membership usually costs between $1,500 and $20,000 per year (depending on company size), LOT is waiving the fees for two years for startups joining through this program.

First, Google’s moves in patents highlights a couple of very interesting developments for the company. It underscores Google’s bigger push in getting more tech companies to collectively act together to fight some of the negative aspects of intellectual property ownership, specifically around lawsuits that are less about safeguarding IP and more about making money.

Second, it’s yet another example of how Google is positioning itself as a broker and portal for all things patent-related. Just last week Google made a significant upgrade to its patent search features, by incorporating search results from Google Scholar and its prior art database. And although the patent marketplace has been launched on a very limited basis so far, it seems like a good way of testing out features that could potentially be made more permanent in the long run.

Google has made a lot of headway into verticals like shopping, travel and media. And as the company continues to grow, I would not be surprised.