I am not sure if this has been suggested before but here it goes...

since its the "Business District" it should be all about business.

but the sad part is that it is getting less and less active and contains litle amount of effort on the roleplay side

the idea is this.

1- one must buy a lot to build a business district

(this will limit the amount of businesses one can make)

2- the more visitors the business gets the higher the percentage of income BUT the income is split into 3 (first for the GF, second for the owner's crew leader, third for the owner) ex: each visitor is equivilant to 50$ equivilant to 5%

(this will motivate people to open a new business) 

3- each business is rated by the amount of visitors it recieves thus the higher the number of visitors the higher the rating and the higher the percentage of income will be

(this will motivate business owners to invite their family or other members)

How would you quantify a "visit"? Is it simply someone clicking on the thread or is it someone actually posting in it? How do these visits equate into monetary values?

I know there was originally a code in place for rating threads and responses ({And I believe something similar is now used for the info stats}) so I guess that could be incorporated into something like this.

a visit is when someone walks in, interacts and leaves as in (posts)

the maximum number of posts I have ever seen on a thread was a while back and it was around 800 or 900 not sure so to limit the percentage we can set for ex: 10000 as 100% profit and go from there

Ahh, the .org approach.

As a player of both games, I can say that the idea you propose is unlikely to increase interest in the business district. People will only post if they want to RP, and whilst it will benefit the owners of a place it won’t necessarily increase

1- one must buy a lot to build a business district

How will this improve the Business district? You say it’s poorly utilised at the minute, surely this would put people off further?

2- the more visitors the business gets the higher the percentage of income BUT the income is split into 3 (first for the GF, second for the owner's crew leader, third for the owner) ex: each visitor is equivilant to 50$ equivilant to 5%

Your second point again relies on people visiting to make money. If people aren’t coming, this won’t really help though I guess families could make each family member open a business and then have them all post to create the $50 to increase tax, but would defeat the logic and have people posting for the sake of posting which wouldn’t increase the quality of RP.

3- each business is rated by the amount of visitors it recieves thus the higher the number of visitors the higher the rating and the higher the percentage of income will be

Again, will likely lead to spamming to up the rating and income but not increase quality.

I don't want to put a massive downer on your idea. But I've seen this on other games. It doesn't increase RP in the way you'd want, it just leads to intentional spamming with nobody really putting thought into it.