There are a lot of people making a lot of money by teaching folks how to sell things on LinkedIn right now. You’ve probably seen an e-book or seminar for sale yourself. If you google “LinkedIn lead generation”, the first result (at the time of writing) is from LinkedIn themselves, and it takes you to a splash page selling their premium tools designed for that purpose. The next three results are for businesses that offer training to marketers to sell things on LinkedIn, and the next two are for articles offering strategies to sell things on LinkedIn. I cannot personally vet or declaim any of these specific trainings or strategies or businesses, as I have not tried any of them. But I will offer a word of advice to anyone considering investing heavily in LinkedIn lead generation.

When approaching online marketing training offers I always maintain a healthy dose of skepticism by  asking these questions: is the seller practicing what she preaches? And has the seller found it more profitable to train others to do something than to actually do it? I’ll give you an example. When bitcoin was still a relatively new and increasingly profitable thing, I was researching how it worked as a matter of curiosity. There are a finite number of bitcoins by design, and each is represented by a long and complex key. You acquire bitcoins by “mining” them, using the processing power of a computer or server to run through millions of permutations of keys until you stumble on the combination belonging to a bitcoin. At the height (or a touch past the apex) of the bitcoin craze, I remarked to a programmer friend that there were companies selling dedicated hard drives just for the purpose of mining bitcoins. He responded, “That’s how you know that the bitcoin bubble is about to burst. If the bitcoin miners were worth what they cost to buy, then the company would be running them instead of selling them.”

I was dumbfounded. He was completely right, and that simple fact had never occurred to me. I would like to think that I would have come to the same conclusion on my own had I been interested enough to actually consider investing in a bitcoin miner, rather than just reading up out of curiosity, but I certainly wondered how many hopeful investors had spent good money on bitcoin miners without ever realizing that simple fact. I always keep this in mind when someone on the internet is offering to sell me something to make me a better and more informed marketer. If the strategy being sold actually worked, would the seller be making more money by using it rather than selling it? Of course, this isn’t necessarily always the case. As a marketing consultant, I sell my time and expertise in building strategies to help other companies reach their next-stage growth milestones. At the same time, I employ many of the same strategies I recommend to my clients for my own marketing and lead generation purposes. Doing and training others to do, in my case, aren’t at odds with one another.

But here’s what gives me pause with the LinkedIn question: of all the times I’ve been offered seminars or training courses or books on how to sell things on LinkedIn, none of the offers actually came to me via LinkedIn. I maintain a relatively consistent presence on the professional networking site, but the offers aren’t there—or at least I haven’t seen them there. If the marketing gurus that found me were so confident that you can generate leads, build a sales funnel, and sell things on LinkedIn, wouldn’t they be doing so themselves? Of course, some are. But I found it ironic that of all the systems being advertised directly to me, all of them had come through secondary marketing channels, namely affiliate marketing within blogs that I subscribe to and direct PPC ads on relevant websites.

All of that said, I actually do think that there is a way to drum up business on LinkedIn, but it involves making a very important distinction, and remembering a golden rule of social selling. The first thing to keep in mind is that there is a huge difference between a warm and a cold lead. I’ll go on record right now saying that I don’t think you can make any money by reaching out to strangers and trying to sell them things via LinkedIn. It just isn’t a good platform for cold lead generation. You don’t go there to buy things, you go to look for professional opportunities, and so is everyone else. However—and this is key—I think that LinkedIn is an invaluable platform for professional follow-up that should be incorporated into any complex sales funnel. In a nutshell, I think that a marketing consultant can follow up on LinkedIn with someone they met at a dinner party, and so end up making a sale with someone who would have otherwise forgotten about them. But I don’t think you can profitably use LinkedIn to message random Personal Trainers who live in the Greater New York area to sell them protein shakes.

The difference in those two approaches hinges on the golden rule of social selling: the same rules apply to online social networking as in-person socialization. You probably wouldn’t walk up to a stranger, ask to be their friend, and then ask them to buy your protein shakes. That’s the real-life equivalent of cold lead generation online. Your first interaction with someone you don’t know should never be to ask them for a favor. And I don’t care how good your product is—if you’re asking a stranger to buy something right after introducing yourself, you’re asking them for a favor.

In summary, I think that LinkedIn is an excellent tool to facilitate low-pressure follow up with a person that you only know in a business context, and that makes it invaluable to anyone with a lengthy or complex sale cycle. But LinkedIn should never be something you use to ask strangers to buy. You might get lucky a few times, but it is ultimately unsustainable as a cold lead generation tool.