DLM/EV was so succesful in the mid 1970 because of the following

(Please correct me if I am wrong, because it is just an estimated guess.)

1. young people experimented with drugs and through that got interested in spirituality (getting high without drugs)
2. Idealistic people were disillusioned in changing the world thru political means and then sought something else. At that time Guru Maharaj Ji popped up who claimed he could bring peace to the world
3. As with any religious movement, people joined because they were looking for a way to give meaning to their life and because they were looking for community with like minded people
4. Maharaj ji gave a rather simple message that he brought with absolute certainty. It was not difficult intellectually and satisfying emotionally because he proposed himself as an object for attachment (i.e. surrender to me) and as a loving mother/father-guru etc.

I find Mike Finch' article about the different types of followers very insightful http://www.mikefinch.org/mj/art/cat.htm

Differences between SSB and DLM/EV (more than an est. guess)

1. SSB never never went to the West. This has the advantage for him that he can control his environment which he may be necessary for him to avoid "testing of the guru" that he recommends and to impress visitors with stages miracles.

2. SSB shows no trace of a regular succession of another guru.
(when he was 14 when he claimed to be a reincarnation of Shirdi Sai)

3. SSB is Hindu, not Sant Mat, like Rawat. Though Rawat strongly deviated from the Sant Mat tradition.

4. Followers generally do not live in ashrams, unlike early DLM, though many people visit his ashrams in India. But you are not allowed to stay IN the ashrams anymore for a long time. Some people buy flats near the ashram.

5. SSB has teachings, not only meditation techniques. Meditation is not that important in SSB's teachings. Related to that is the fact that followers of SSB are not so extremely oriented on experience.

6. SSB is far more stable in his organization and his teachings though the latter sometimes contradict.

7. SSB made unequivocal claims of divinity (claims to be the Messiah and the Kalki avatar) that he never strongly contradicted with other claims

8. With regards to meditation, SSB never said that he was necessary for successful meditation

9. SSB claims to perform miracles, not only sleight of hand aterialization, but also bilocation, healing of the sick, remote vibuthi manifestatiions. Rawat's followers merely attributed coincidences to Providence

10. It is even more difficult to get access to SSB than to Rawat

11. Sexual abuses by SSB has been well documented, unlike Rawat

12. SSB said that everything he does has meaning. So followers always seek meaning in what he does including sexual abuse by SSB which they inititally interpret as "kundalini awakening", or helping with sexual problems.

13. SSB'org receives a lot of donations. Biggest recipient of overseas donations in India

14. SSB has high ranking Indian politicians as his friends, who protect him. Some are his sincere devotees but in other cases it is probably related to point 13. Money

15. SSB promotes charity and exhorts his followers to do charity .

16. An important way of recruiting followers is thru books by and about SSB (public library here has dozens of them).