I've been around the block on this topic a few times. Here are my observations.

Booths at conventions are a waste of time, they do not actually generate any share price appreciation of sales of stock.

IR companies can be good if they do more than fill up a room at lunch or afterhours for a bunch of freeloaders. Those events tend to be more networking than anything else. If the IR company sets up 1 on 1 meetings afterwards with interested parties, then that is of interest. IR companies usually get a decent mix of brokers and institutions out, but it depends on the company.

Promoters are always a great way of rocking a stock. However, they will not get people in who will understand the story, they are simply very effective sales people.

At any rate, in these markets, not much is working.