You did not mention if its a monthly investment or a once of investment. I will take it as a once off investment. What also make this question difficult is that I dont know what you already have by means of size of downline, ECA store and where does you interest lie.
I personally will invest most of the money into PPC or PPA advertising. With $500 you can bring in a lot of new affiliates by advertising with the correct people.
Then I will also invest in about 2 S-builder units, I will buy 90 gift cards to build my PRM's.
Like I said I will recommend to use most of the money in building your downline.
You did not mention if its a monthly investment or a once of investment. I will take it as a once off investment. What also make this question difficult is that I dont know what you already have by means of size of downline, ECA store and where does you interest lie.
I personally will invest most of the money into PPC or PPA advertising. With $500 you can bring in a lot of new affiliates by advertising with the correct people.