From the commercial side of things, there is no doubt that the club is doing its best so far despite the relative lack of success. The brand is so powerful that it can produce such numbers but you can't take away that club's previous success played a big part in building those figures.
It allowed the club to develop itself mostly through Commercial sector or sponsorship deals (more than 60 official partners worldwide including Adidas). So, the commercial sector did grow from around £50 million in revenue to around £270 million from 2006 to 2016. Broadcasting revenue also played a significant part in it. But, as I said, it is all being done based on Man Utd status as the biggest English club which status is achieved during Ferguson era. Most of the sponsorship deals were signed shortly after that period. If our performances on the pitch in EPL remain around 4-6 place you will see these numbers go down in a few years so that's the point that I was making. It doesn't take such a long period of time. We were desperate for a reason to get ourselves in CL this season because we knew that we could be hurt by missing out again.
Also, no matter how big those figures above are, what's frightening is that they should be higher but they aren't due to our struggles on the pitch. For example, lack of EPL success hurt us. Leicester manage to enter in top 20 highest revenue-generating club in 2015/16 thanks to their title winning campaign. City boosted their revenues in 2015/16 massively due to their success in CL campaign getting about €83m as you see in the link:
http://www.uefa.com/uefachampionsleague/news/newsid=2418253.html
So, all those figures are nice but due to the lack of big success they should be even bigger and if that continues we will not be able to keep them so high. That's the reason why when talking about a new player such as Bale he should be considered mostly by his potential to help us on the pitch. And I'm not saying he can't help us, just that such measure must be the first one when we're buying a player.