We could have 50 boxes but it wouldn't matter a jot because we can hardly get enough takers for the nine we've got, and one of them those 9 is generally leased by a player. That's just were we are as a club, our fans on the whole aren't wealthy and we as a club aren't glamorous enough to attract business away from our competitors.
Also the only other none new stadium I can think of that's had a name change due to sponsorship was the SportsDirect stadium, I'm not sure how much was paid but it clearly wasn't a successful venture as it didn't last long and is now back to St.James Park. Although I personally wouldn't like to see us sell out from calling the ground Goodison Park to whatever sponsors we could find, I suppose any untapped revenue stream is an improvement on not tapping it.
We clearly need to either find a new home or restructure Goodison into a modern facility, but it's not whats holding Everton back from competing at the top. The real problem is the fact we've not go wealthy owners who are willing to throw money hand over fist at the club. Bring in an extra £5-10m per season won't suddenly make us champion contenders, it may well fund an extra player now and then but it won't revolutionize us like some people claim.