As long as you are using original content and adding value then your rankings will gain and you have more strength for pr, vouchers, deals, cross promotion, following and customer base but there are other considerations when moving from an affiliate to a retail model and it will change the way you work, even with drop ship agreements so I would consider these factors when making a decision.
a) Now your processing money and buying stock so you need to make sure your cashflow can accommodate the demand as if your going through a merchant or say paypal obviously it can take 7 days for money to reach you then maybe a couple to reach your credit card, but you have to buy the stock on order in most cases.
b) You are responsible for any chargebacks so make sure your margins can accommodate these losses (the rate will differ with the industry as well so an factor to consider when choosing a product)
c) If you are UK based you bound by long distance selling regulations, your suppliers are not and will often refuse returns or charge a restocking fee. If they refuse then you have to accommodate for holding, repackaging and re-distributing stock.
d) Returns again, if faulty you will need to look at your suppliers terms and factor that you may want stock (or it may be done by mistake by the customer) sent to your address to check (also photography) and send onto your supplier, again time and expense.
e) Lastly you will now be the retailer and as such customer service is all on you so accommodate for taking and managing sales inquiries, a telephone number will increase your conversion (but they will try and give you credit card details over the phone and you will loose some sales this way if you don't have this facility (personally i weighed up the pros and cons and decided the loss of sales was negligible compared to the risks and time lost offering this service)
f) When choosing a dropshipper note the points above and also how they keep you updated with stock levels, their turn around and others experiences and also accommodate for time to keep stock levels upto date etc, as it can quickly damage your reputation if you are getting reviews of out of stock orders etc.
g) Last, geek time, now you will be processing your products I would make sure your checkout is as smooth and easy as possible, allowing new users to buy easily and an account automatically set up for them.
It has its benefits, it has its drawbacks, it all depends on how you want to work as to whether this model will work for you. These are the pit falls I have come across but I do enjoy having real contact with the customer and controlling the sales process environment and ethos of the business. But hey i am a bit of a control freak anyway, hence why I ended up a geek in the first place!
I hope this helps with your decision
Good luck and please keep us informed on how you get on!