The problem is we as engin-nerds don't want to pay for something nebulous like marketing, with no proof that it pays off. And back before the Internet, that was the world of advertising. How do you track if that crazy expensive billboard in Times Square was seen by people and resulted in an uptick in sales? But thanks to tracking, it's easier to quantifiy results.
Time is money so I'd suggest finding somewhere/someone and giving them the money for their expertise, but it doesn't takes much time, you could do it yourself. Create a Google AdWords account and buy AdWords for "wedding planning seating chart" or other combination, and see how many hits you get for that, and judge for yourself if it's worth it. A competitor (zola.com) already has the first result for that, but that should be enough to for you started. My email's in my bio if you want to chat more.
PPC used to be very lucrative, but the bid prices have inflated to the point that it is increasingly borderline. I'm currently turning PPC on and off alternate weeks to try and see if the ROI is positive. This is an off week.
