I think you missed my point, so I'll explain another way because I think it's important to make.

If you look at the TCP packet, bits 16-31 are constant for all HTTP traffic. Because they are a fixed value, they're wasted (non-unique). With the current system, we can only have 2,147,483,647 web servers.

Using SRV records, these bits become distinguishable, giving us 281,474,976,710,656 possible addresses for web servers.

[Yes this is an oversimplification for the pedantic]