The difference will be the common benefits - whether or not there's a pool, tennis courts, "free" cable, etc.

I stacked hay, drove tractor, balers, seeders, and other farm implements, broke horses, trained race horses, jockeyed, trimmed trees, shoveled snow, worked at several gas stations, painted houses, painted coal dredges, security guard, roto tilled yards, planted flowers and gardens for folks, raked leaves/yardwork, eventually worked oil field when it was booming, even crawled in tunnels installing coaxial cables and fiber optics, loaded explosives in seismic testing holes, eventually a lawyer, and landlord. 

They pay for Internet and cable on their own.

A few ideas, all of which require research and feasibility assessment as they depend on local regulations and/or affordability / demand in your market:1) add additional lots by developing unutilized land2) add storage space / shed for residents to rent for a monthly fee3) offer a cable or bundled cable / phone / technology package to residents; buy services at wholesale rates and sell to residents at discounted retail rates4) adjust rents based on size / location / views/ambience of lots in the park5) bill back water/sewer/trash, where applicable 6) offer billboard/advertising space if your park has decent traffic visibility7) lease space on property for cell tower operator 8) cut grass on residents’ lots for a fee9) paint/wash/skirt homes of residents for a fee10) fill vacant lots / vacant land with area for long-term parking for boat/RV/equipment 

$100 is a round number and kind of low.What about internet/cable?

I would do cable boxes in both living areas and the master bedroom at the least.

These apartments include all utilities and cable (I know right?).

Anything beyond that (cable, wifi, Netflix, outdoor grill, etc) is a bonus to them. 

I have high-speed Internet, so they can stream from their own devices, and I tell them to bring an HDMI cable if they want to do that. 

You pay utilities and cable, rather than your tenants.