I think a lot of rock bands need to get it through their skulls that they're simply not going to fill stadiums and large venues anymore. Cater to the right size crowd at the right venue and you'll get results.
Unless you're a super duper mega act (AC/DC, Metallica, U2) or have a HUGE cult following (Pearl Jam), I agree that I think most bands should look into performing at more smaller venues and do more intimate shows. I might be off, but I think alot of these amphitheatere style shows are killing sales as well. I get that during the summer that people want to be outside drinking a cold one and listening to music. In that case, I think summer tours should be strictly festival type shows, or have more Bonnaroo or Lollapalooza type shows where you have a TON of bands at one central location. Granted, those shows are steep in price and you would have to travel to the location, but I think in general you get more bang for your buck in regards to the number of bands playing. I DO like the idea of taking two established bands and having them peform one of their albums from front to back. Sell the ticket at a great price, include discounts like 4 tickets for $50 kind of deal for lawn seats. Imagine IF Alice in Chains and STP teamed up with STP playing Purple and AIC playing Dirt for example?
Back to the outdoor shows though, it seems like year after year, I look at the back of the lawn, and fewer and fewer people show up. Is it because of the oversaturation of the market? Ticket prices and fees? (Probably) In that case, if an act hits big, have them team up with another steady act that would garner more sales. For example, let's take Kings of Leon. They are doing an amphitheatere type tour this summer. I have no idea how their sales have been, but I think they would benefit them from touring with another semi-big indie band with a cult following (My Morning Jacket) or one who is still somewhat under the radar (Band of Horses or Okkervil River) instead of going out on their own just solely based on the success of Only By The Night.