Over 500 million tweets a day are posted on Twitter, so it's almost impossible to trend on the back of a single tweet. To trend, the hashtag or tweet has to influence others, it has to spread, it has to beat 499 million 990 thousand and 99 others tweets. I've trended on Twitter as 'craigstone_' which shows that it is possible to create a trend.
Whether a business if just starting out or already established, if it trends on Twitter - it's big business.