1) Both believe in reincarnation.
2) Both believe there are many different paths to enlightenment.
3) Both believe that our suffering is caused by excessive attachment to things and people in the physical world.
4) Both believe in an ultimate spiritual reality beyond the illusions of the physical world.
5) Both practice meditation and other forms of yoga.
6) Both believe that eventually all living spirits will achieve enlightenment and liberation, even if it takes many incarnations.Remember that in Mahayana Buddhism, the original teachings of the Buddha are assimilated to Hindu practices, including prayers, gods (even the Buddha as god in all his many incarnations). Mahayana Buddhism also introduces the idea of (temporary) heavens and hells. 

Buddhism was accepted both by common folk and upper castes especially the main patrons were merchant community who donated vast amounts of money for buddhist activities. Most of the king's wives and moms became followers of buddhism and made donations for stupas and buddhist shramanakas. so how come it disappeared from india, you wonder all that charity and benovolance attracted lot of riff-raff into buddhism making the people hate the bhikkus and bhikkunis. Hindu society is based on work based castes, each caste had its own place in society because they performed certain acts which are in turn like wheels chugging the scoiety machinery.
Bhikkus and Bhikkunis did not have any specific act to be performed except they wanted societies charity for ever. Hinduism in turn accepted the best things taught by buddha and elevated him to one of the avatars of Lord Vishnu. people who were attracted to buddhism before found their calling back to hinduism when Adi Shankara appeared on scens along with Ramanuja attracted these lost people to hindu fold. My state had lot of buddhist history and we are finding so many things through archeological excavacations. i love buddhas teachings and find comparable things in my own religion. i do not feel i am away from hinduism as the core concepts of buddha actually exist in hinduism itself. This hindu prince who is one of the greatest humanitarians ever lived on earth.

thank you so much Kaushal kumar, your information helped me a lot! REALLY THANK YOU !!

[11] भगवान् बुद्ध शूरसेन जनपद में एक बार मथुरा गए थे, जहाँ आनंद ने उन्हें उरुमुंड पर्वत पर स्थित गहरे नीले रंग का एक हरा-भरा वन दिखलाया था।[12] मिलिन्दपन्ह[13] में इसका वर्णन भारत के प्रसिद्ध स्थानों में हुआ है। इसी ग्रंथ में प्रसिद्ध नगरों एवम् उनके निवासियों के नाम के एक प्रसंग में माधुर का (मथुरा के निवासी का भी उल्लेख मिलता है[14] जिससे ज्ञात होता है कि राजा मिलिंद (मिनांडर) के समय (150 ई. पू.) मथुरा नगर पालि परंपरा में एक प्रतिष्ठित नगर के रूप में विख्यात हो चुका था।

visit http://bharatdiscovery.org/india/बौद्ध धर्म

अवस्थानुसार उत्तर या मध्यम अर्थदंड दिया जाता था (जेम्स लेग्गे, दि टे्रवेल्स ऑफ फ़ाह्यान, पृ 43)। अपराधों की पुनरावृत्ति होने पर दाहिना हाथ काट दिया जाता था। फ़ाह्यान लिखता हैं कि पूरे राज्य में चांडालों को छोड़कर कोई निवासी जीव-हिंसा नहीं करता था।
मद्यपान नहीं किया जाता था और न ही लहसुन-प्याज का सेवन किया जाता था। चांडाल (दस्यु) नगर के बाहर निवास करते थे। क्रय-विक्रय में सिक्कों एवं कौड़ियों का प्रचलन था (जेम्स लेग्गे, दि टे्रवेल्स ऑफ फ़ाह्यान, पृ 43)। बौद्ध ग्रंथों में शूरसेन के शासक अवंति पुत्र की चर्चा है, जो उज्जयिनी के राजवंश से संबंधित था। इस शासक ने बुद्ध के एक शिष्य महाकाच्यायन से ब्राह्मण धर्म पर वाद-विवाद भी किया था।