Just to expand on the "rewards" of social points, as it's been said you can only equip certain items if you have a high enough social score. Some examples, Nar Shaddaa Social Vendor has Slave Metal Bikini gear, and Tatooine has Sand People gear, btw these are orange/custom gear, so you could potentially make them comparable to your other gear with mods. But some social vendor's all sell stuff like Speeders that you can only use with a high enough social score, so yeah mostly for RP uses, but there are alternate perks to the system as well.
"Women are like sunsets… they’re beautiful, but there will be a different one tomorrow." - Gilder