I like that LoopNet is a very accessible and social version of other real estate databases like Xceligent or CoStar. Anybody can make a free account and start searching. It opens up the mysterious world of commercial real estate to the public. It allows brokers to advertise much more than other platforms.
LoopNet is a good resource for industry news.
Some residential brokers will put things on LoopNet but not on CoStar. Some commercial brokers will put listings on CoStar but not on LoopNet. I dislike the need to search and cross reference multiple sources to find out the true information. I find myself starting with CoStar (because it's my best chance), cross referencing with Xceligent (because I'm likely to get a good feel), and then last resort go to LoopNet. While LoopNet is a good source for industry news, it's not such a reliable source for detailed information on properties.
If CoStar is the MLS of commercial properties, LoopNet is Zillow.
If you're going to pay for LoopNet premium, consider alternatives. Having a Basic account is free and I would highly recommend to anybody who wants or needs to know information on commercial properties. Is it a perfectly curated database of properties? No. But it is a good jumping on point that can give you enough information to dig deeper.
LoopNet allows the public to inform themselves on some commercial real estate. I use it to pose questions to the public, advertise my services, and learn about industry trends.