People love to save money on products and find great deals online!
As an affiliate marketer, you should leverage this mindset. It's one way you can stand out in your niche, and really serve your market.
There are many CPA Networks, such as Escalate Media (one that I like working with), where you can promote current special offers and coupons/deals. Many of those offers are for bigger well-known brands, and they run for a very short time.
CPA offers are great but they make for higher-maintenance marketing, as you have to remove/replace the links when offers end. Still, they tend to convert very well.
Price comparisons & current deals can be hard to stay on top of too, especially if you're finding and posting them manually. But what if you could automate the whole process and always have current prices and sales available for your readers? 
Datafeedr makes it super easy to build an online store as an affiliate, and automatically update your site or blog with price comparisons from various merchants you are an affiliate for:
There's also an option to drip content with current deals and offers from your affiliate merchants as well, and/or to create a category that is automatically updated with coupons and specials to help your visitors find the best deal:
Nice, right?  Obviously features like this will increase your conversions as you are giving buy-ready visitors the absolute best deal online.
Speaking of buy-ready visitors, people ARE shopping online with credit card in hand, and they ARE buying physical products. Especially when they can find great deals!
Just to give you some inspiration and a few real-life examples, here are current "shopping" keyword phrases being searched right now, according to WordTracker (my favorite FREE keyword research tool):
buy leather wallets 647
  buy appliances 598
  best tv to buy 589
  buy appliance 462
  buy fridge freezer 447
  buy freezer 436
  buy hotpoint fridge freezers 430
  buy chest freezer 429
  buy books online 404
  buy bosch fridge freezers 400
  buy bosch freezers 390
  buy refrigerator 387
  buy a freezer 374
  buy hotpoint freezers 361
  shoes buy online 358
  buy fridge freezer online 339
  buy upright freezer 309
  buy washer dryer 290
  buy washing machine 286
  what bike to buy 270
  buy dvds online 248
  buy dvds 218
  buy cigars online 215
  buy textbooks 207
  buy ipad 203
  buy washing machine online 197
  buy books 194
  buy washing machines 191
  buy refrigerators 179
  buy contact lenses online 175
  buy bath salts online 119
  buy digital picture frames online 119
  buy cookers online 113
  buy lingerie online 100
  buy cooker hood online 98
  buy shoes online 98
  buy refrigerator online 97
  buy eyeglasses online 96
  buy vinyl records online 92
  buy tires online 83
  buy dumbbells online 82
  buy microwave online 79
  buy toaster online 79
  buy contacts online 71
  buy wine online 70
  buy steaks online 69
See what I did there? I used the word "buy" as a keyword modifier to find buyers specifically. People in a buying mindset.
Obviously you can take one word, such as "microwave", and go to WordTracker to find out what people are searching for specifically for any given product. This will give you tons more longtail keyword phrases with even more search volume!
And of course people ARE searching for good deals, best prices and price comparisons on the products they want to buy online:
best price 460
  best price fridge freezers 436
  best price on dewalt 36 volt jig saw without battery or charger 391
  merrell shoes best price 305
  ipad best price 207
  windows 7 best price 179
  best price cruises 158
  ipad 2 best price 136
  best tire prices 136
  best price k cups 133
compare prices 716
  compare natural gas prices 434
  compare fridge freezer prices 404
  compare hotel prices 378
  compare freezer prices 375
  compare book prices 267
  compare washing machine prices 207
  compare cooker prices 113
  compare fridge prices 106
  compare prices online 102
fridge freezer price comparison 366
  price comparison 263
  price comparison service 184
  washing machine price comparison 139
  cookers price comparison 122
  fridge price comparison 99
  refrigerator price comparison 94
  hotel price comparison 85
People WANT to buy products online!
Your job as an affiliate is to help them make an informed buying decision, and help them find the best product - and the best deal on that product. 
DataFeedr is a great option for creating a product-based affiliate site targeting buyers, with price comparison charts from top merchants, and current coupons and deals. Check out all the features here. I love their new automation features, as I mentioned in my post on using them as an ideal affiliate store builder.
I mentioned Escalate Network earlier, for CPA offers. They DO offer a widget you can put in your sidebar, which would go great with your DataFeedr affiliate site. You can see an example to the right.
The deals & offers are automatically updated, based on your categories, and you have full control over which ads display there too. Which is another great way to offer deals to your visitors without having to constantly update or replace those offers!
I hope this gives you some ideas to work with, and inspires you to meet the needs of your market by creating sites (or adding a store to your site) that sell products people really want to buy! 
Best,
p.s. I would love to hear your thoughts! Do you currently promote physical products as an affiliate? Why or why not?
* This post contains referral and/or affiliate links for WordTracker, Escalate Network and DataFeedr, which means I will be compensated if you sign up for those services. Of course, I'm only recommending them to you because I use them myself!
