Yes, that's true, the companies that have active campaigns are the ones which people trust more than those that don't have campaigns. Similarly, the ones that do have campaigns get more exposure than the ones with no campaigns and that's a reality.
It's not only campaigns that is important for people to trust some service, but it certainly helps.
I would say that working with community is always a good thing, and than people can spread the word around if they are happy.
Mixtum reputation was built in bitcointalk forum, but it continues here.
Yeah, you are absolutely right, Mixtum began their marketing journey on bitcointalk if I am not mistaken, there also they began building their reputation and thank goodness for the level of trust the community have in them today..
Running a campaign does not automatically build trust and reputation, we have companies like 1xbit to use as an example, they ran a campaign on bitcointalk for years but were never trusted, at a point, DT forum members started tagging any account found to be wearing their signature ad with negative trust.
So, reputation and trust is much more based on how a company serves and treat their users or customers, rather than the marketing method they choose to run.