AOL is raising the subscription fee by 20 percent for its low-cost dial-up service plan, a move that illuminates an awkward phase of its transition from an Internet service provider to an online media and advertising company. The Time Warner division told subscribers last week that beginning July 27, it would raise its monthly dial-up rate from $9.99 to $11.99 per month. Subscribers who specifically sign up for a plan with limited technical support can keep the $9.99 rate, though, but they won’t get phone-based help unless dealing with an Internet connection issue. AOL lost 647,000 subscribers in the first quarter of 2008, dropping to a still impressive 8.7 million in the United States, but clearly the company hopes not to lose more. Losing subscribers and their $120 a year is an obvious downside for AOL. But a more subtle problem is that losing subscribers could hurt the online business that’s AOL’s future. That’s because AOL subscribers happen to own a lot of the eyeballs visiting AOL’s Web properties and watching AOL-delivered advertisements. Well, we’ll see what is to happen.