I see many people, many professionals on this site in particular, use a comma after an "and" that does not act as a conjunctive in a compound sentence; for example, many people would place a comma here:
I went to the nearby cafeteria, and ate quite a lot of food
A far more witty example of this would be the use of a comma after the phrase "and also", where there clearly seems to be some sort of a pause - especially in longer or compound sentences or in ones where different verbs are used:
From this we can see that the author was trying to emphasise the good relationship between the two protagonists of the story, and also used the technique of alliteration for that purpose
What I think about this is that "and also" may be acting the same role as "namely" in sentences such as, "I was playing football with my friends, namely Geoff and George" - like a conjunctive to join a main clause and a subordinate clause. However, this still wouldn't explain why comma is used before "and".