 What's stopping you from investing in the stock market? Student loan debt? A paycheck that doesn't leave much wiggle room? Did the 2008 crisis leave a bad taste in your mouth? Maybe you just don't know where to start. If that's the case, many young investors are jumping into the market by buying up stocks from companies that have products they like to use. But is that a good strategy? Is that a smart strategy? Is this a strategy at all? Let's take a closer look. On the day Snap went public, activity on Robinhood, which is an app that lets users buy stocks commission free, surged. 43% of their users bought shares that day, according to the Wall Street Journal. Guess what? Snap surged right along with it. The company's shares ended the first day of trading up 44%. If you bought Snap because you like using Snapchat, it looked like a good bet. But the good times didn't last much longer than a photo last on Snapchat. The stock quickly tumbled. If you stuck with the stock through August, you and CEO Evan Spiegel were both down 50% while he lost more than you did at the end of the day, he's still a billionaire. But there is something to be said about this strategy. The top holdings of TD Ameritrade's millennial clients for the month of June included Apple, Facebook, and Amazon. Each of these companies makes a compelling argument for buying the companies that you use. Year-to-date, Apple is up 40%. Facebook is higher by 49% and Amazon surged 31%. So is it fair to compare these more established companies to a newcomer like Snap? That's not what we're doing here. We're looking at the buy what you like strategy. If you like Apple, Facebook, or Amazon, you would have done very well. So this is my take. If you love a product enough that you want to invest in the company that makes it, you might strike gold, but you could also end up losing your shirt. Let's face it, people have purchased stocks for worse reasons than liking their products. Just remember, you might love a brand, but Wall Street doesn't necessarily feel the same way. Just look at Twitter. So always do your research. Always look at things like price to earnings ratios. Check the competition and know the industry trends. But if you're not confident or you don't have the time to do the work, the safer bet is often looking at index funds, which allow you to spread your risk across companies that you already love and some that you've never heard of.