I've never been involved in that segment of investing.

Sure Boston has other industries, and college kids make a huge segment of the rental population in the city (and Cambridge, Somerville, Medford, Watertown, etc.). 

Once that's established, then write your book with the intent on filling that need.For instance, after some research you you learned that a large segment of young professionals have an interest in taking advantage of the downturn in the economy and want to purchase investment properties.

For that segment doing guru junk from a place of genuine ignorance, this will make it explicitly clear that what they are doing is predatory and wrong, and hopefully they will stop. 

Certain segments of the population tend to have more children than others.

In fact, in stark contrast to that idea, the 2003-2004 vintage of sub-prime loans is actually the best performing segment of loans within the 2003 to 2007 vintages with a default rate below 6%.

Personally, trying to break brokerages down into age segments, and finding a way to market specifically to them (which you'd need to be careful about due to discrimination issues) I'm not seeing the value in it. 

These example scenarios show the impact of marketing to your high/low quality segments accordingly.

Talk to the sales department at a few of those places and see if you can find someone that focuses on this segment. 

I went to Detroit and was lending money to flippers in 02 to 05 did hundreds of HM flipping loans to every segment of community.