FORTUNE — If you’re going to model your business after an industry leader, you could do a lot worse than looking to LinkedIn. The professional networking site’s rise has been impressive, to say the least. Just read Fortune’s recent cover story if you need convincing. The site has more users than ever, all spending more time on the site, either updating their profiles, searching for jobs, or simply reading unique content. (LinkedIn does that now, too.)
While LinkedIn LNKD caters to all industries, other professional networking sites have cropped up that attempt to serve specific niches. These aren’t necessarily LinkedIn competitors. They offer similar services, but to a much smaller user base. They say imitation is the most sincere form of flattery, so here are some of the unique professional networks that may remind you of a certain juggernaut:
1. Rally Point. The military is well-known for being up to speed on the world’s newest technology. When it comes to LinkedIn, however, the military is remarkably late to the game, says Yinon Weiss, CEO and co-founder of Rally Point. It’s not that LinkedIn doesn’t cater to military members, it’s that military members have no clue what LinkedIn is, he explains. Even the basic concept of networking can be perceived as brown-nosing in the military, and Rally Point is meant to help both active military members and veterans translate their military experience to a civilian audience. “Part of the challenge that we have is educating people and informing them that there can be a lot of positive value from building a network,” says Weiss, who served 10 years of active duty before attending Harvard Business School.
The site launched less than a year ago and just opened up to veterans on Memorial Day. The company has received $1.7 million in seed funding in the past 18 months, and with 25,000 members already signed up, Rally Point continues to focus on growth, says Weiss.
2. Ballers Bridge. You may get in hot water with the NCAA by calling this site a “professional” network, but Ballers Bridge is certainly putting a more formal spin on collegiate basketball recruiting. While superstar high school players may have college coaches knocking down their doors with scholarship opportunities, the recruiting process is quite different for the mid- and lower-tier athletes looking to snag a scholarship. This is the market Ballers Bridge looks to address. This social network is tailored to high school basketball players who need to network and sell themselves to coaches in order to get noticed, says CEO Gerald Cannon, a former college player at Morehouse College in Atlanta. After extensive conversations with college coaches around the country, founders Cannon and Armand Brown put together a site where players can present coaches exactly what they want — bios, academic records, and most importantly, entire game films, not just highlight tapes.
The site has over 5,000 users and more than 300 collegiate coaches ready to sign up, he added. “We’re at every camp and clinic we can get our hands on,” says Cannon. The duo said they got NCAA certification to ensure coaches could use the site without running into trouble.
3. edWeb. When edWeb CEO and founder Lisa Schmucki watched how much interaction and communication her daughter was able to achieve using Facebook, she realized there needed to be a safe place for educators to do the same. Too many teachers and education professionals were spooked by traditional social media — they wanted a place away from their socially savvy students. “We are professional only, we are education only, so it becomes a safer place for people to connect with one another,” says Schmucki, a former publisher of educational materials. “We’re about doing it for your work and for your practice.”
Since its founding in 2008, edWeb has attracted more than 65,000 members across all areas of education, from vendors to teachers. Users can create their own profile pages, and much of the interaction comes in the form of collaboration, where users share teaching methods or even lesson plans, says Schmucki. The site has dozens of monthly webinars for users to watch, and users are connected to similar folks by joining community groups, just like LinkedIn. Unlike LinkedIn, the site does not yet offer job postings, although that’s something Schmucki hopes to add in the near future. “I don’t think LinkedIn has this equivalent of professional learning communities,” she says. “I think that’s the vehicle that enables educators to come together into a group that they feel they can trust, and be open with, and learn from.”