when you make a new purchase through a dspp regardless of whether you make a one time purchase or sign up to invest monthly typically you will not have any control over the respective trade date when you use a transfer company the transaction may not happen for a number of weeks basically the purchase goes through at whatever the stock price happens to be at that time 
on the other hand discount brokers allow you to trade in real time so you always know the price a cardinal precept of investing is to diversify your investments so unless you are enrolled in dozens of dspps across multiple industries and internationally or have most of your investments in index funds mutual funds or exchange traded funds etf you may be inadequately diversified in fact just about any individual stock purchase whether direct or broker transacted runs this same risk you need to diversify dspps on their own typically will not do the trick for the average investor although a dspp s associated fees are low it is rare that a plan would have no fees at all many charge initial setup fees and some charge for each purchase transaction as well as sales fees even very small fees can add up over time especially if you are slowly and automatically adding to your position so as with any investment always read a dspp prospectus carefully to see what fees you might be charged special considerationsall things considered the greatest benefit of dspps for individual investors remains the ability to avoid commissions by not going through brokers for some investing in dspps still is a good option for the small investor who is ready to buy individual shares of a particular company to add to their portfolio and hold for the long term a dspp may be a thrifty way to do so 