Both Slack and Dropbox are simple ideas, executed extremely well. I see that for both of them the challenge is there's quite many customers who don't demand the

Both Slack and Dropbox are simple ideas, executed extremely well. I see that for both of them the challenge is there's quite many customers who don't demand the best execution, but can settle for not-so-good-but-a-bit-cheaper alternative. Both companies can probably make well enough money to survive and achieve growth, but maybe not such an exponential growth the investors where expecting.