Hi, I've been running paid media campaigns for companies since 2004. There are some definite advantages to using online ads. It's a great way to build awareness right out of the gate (even pre-launch). You can test messaging & value props much more quickly and effectively when you're paying for exposure than when you're waiting to be discovered.

Paid ads shouldn't be the ONLY channel you use: earned & owned are important too, and to your point they continue to reap benefits over time. Earned & owned may be the marathon to paid media's sprint, but don't overlook the value of paid in driving awareness & feeding the funnel for other efforts.

One final bit of advice if you're considering paid search as part of your paid media; PPC on the Search network tends to be a lot more costly than on Display, and it's not a great tool for awareness generation. Search can be insanely effective if you have either an established brand or a super strong offer in a low-cost niche, but it's a very expensive channel to simply "get the word out" or attempt to scale.