Just like any show, I strongly suggest you visit any event before you book it.
It's true that generally the crafts or vendors are the "side show" for any event, so whether it is good (for you) will depend on multiple factors
- Will your target market be there?
- Are your items good fit for the crowd or the event?
- Where is the vending area? Is it tucked far away? Close to main events, where people will be walking?
- Is there time for people to shop? Different parts of the event that they will be walking around to see, and thus have time to stop and shop? Because if there's just one major concert, people will be busy watching that, and no one will be shopping.
I do some music festivals, street fairs, cultural festivals,and town festivals (the big event that town has every year). Some are handcraft only, some have a craft area separate from the commercial vendor area, and some have commercial and craft vendors mixed together.
For pretty much all the ones I do, I either visited the year before I booked/applied to see for myself what the crowds were like (and if they were shopping), where the booths were located, etc. There were a couple that were too far away to visit, but I had multiple crafter friends recommend these shows.
Based on previous threads I know that others will chime in here and tell you to never do events where crafts are not the main attraction. I don't agree with that as a rule. Just like a regular craft show, there are good events and bad ones, some are well organized, some are not. If people are there for a full day or a full weekend, they have the time to look around and shop (if they can find you) What you sell, and how well it fits a specific event plays a big part too.
As for tactics? Making your booth eye catching as possible so people will stop is more important than at a regular craft sale. Banners with your shop name, banners with photos (especially if your work is small).
I also find that I do have to work a little harder talking to people, to get them to look around longer.
As with any show, it's also important to keep in mind whether you can spare the time and money if it doesn't work out - risk management.