Today internet is rather different with few years ago. Few years ago, internet is very dependent to Tier 1 ISP. If you have many Tier 1 IP Transit, you can have better internet access, because more route can you reach with best path.
Today internet is more distributed. Global content providers have their own network, and locate their servers at many data center at many region or continent. It give more balanced traffic, and break dependency to Tier 1 ISP. Also, regional ISP locate their router, and have own to link to one or more global data center, to reach global content provider and give possibilty to direct peer with others. This architecture give today internet more distributed traffic, and more better route.
The prerequisite if you want peer with regional ISP, global content delivery, or global content provider is to have colocation at global data center, like Equinix, LINX, and others. Check the data center that have Internet Exchange, and who are there through PeeringDB. Register first, it's free, then looks for internet exhange, their customer. Many content provider, content dlivery, or regional ISP is better.
Global content provider like Google, Yahoo, Microsoft are open for peering. It give you benefit by saving IP Transit bandwidth, that must you pay, and give shorter route. For example, Google,about 30% of my internet traffic is coming from them.
Many IP transit now have their own CDN, but it is likely not a free service. Traditional CDN, like Akamai, are open for ISP to partner with them.
Partnering with CDN give benefits. Because it's locally placed at your data center, it can give benefits. The benefits are:
1. Saving international IP Transit bandwidth
2. Faster access
Akamai has program called Akamai Accelerated Partner Program for ISP. It is for ISP that want to place Akamai CDN server at their data center. Akamai has many customer from content provider to software company, like Microsoft, Adobe, and many. One that's looks as a benefit is your Windows Update will be direct to your local data center, because Windows Update are hosted at Akamai server.
I have experience when apply for Akamai Accelerated Partner Program. They looks my ISP AS Number, and they say, our traffic to Akamai content is about 30 Mbps average a day. After they evaluate, and agree, they ask us to provide environment for their servers, like rack, gigabit port, and setup BGP session with them.
Akamai work based on DNS and IP address. Akamai server client based on DNS request, and reply resolved address with nearest Akamai server.
Until now, I have no reference about others CDN that have partner program like Akamai. It's best for your ISP to partner with Akamai. It will saving your international IP Tansit bandwidth, and give faster internet access. And the best thing, it's free at all.