A typical LED product from China

Here's their ad, picked randomly from the web:

==============================================
LED Bulb (PAR30-E27-7W)
Product Description

3-year total unconditional guarantee
MKS-LED unconditional 3 year guarantee allows the consumer to return the broken or damaged light and get new lights immediately in-store, with no questions asked and no down time.
1% free
Furthermore, we supply 1% free light with your order if your order is bigger than 100sets.

Detailed product description:
Model number: MKS-PAR30-E27-7W
Base type: E27
Power: 7W
Input voltage: 85 to 260V AC
Light source: 7 x 1W high-power LED
Luminous flux: 500lm
Body temperature: Less than 48
Temperature: -40 to +70D
Brightness degradation: 3% to 5%/1kh
Lifespan: 50, 000 hours
Aluminum alloy curst and faster scatter thermal diffusion
No UV or IR radiation
Full range of colors: Cool white (6000 to 6, 500K), warm white (2, 800 to 3, 300K), blue, green, red and yellow
Applications: Replacement bulbs for general lighting, especially for museums, art galleries and cosmetic counters where UV or IR radiation is undesirable
============================================

My analysis:

Input voltage: 85 to 260V AC >> This means they use a flyback power supply (PS) to drive their LEDs. Such a flyback PS has at least two small electrolytic capacitors, one for filtering the rectified AC current, the other at the output for smoothing the output voltage of the flyback PS, hence the LED current. They dry up over time, therefore the LED lamp won't last long. Furthermore, its power factor of less than 0.5, which increase power transmission losses from the power plant. Flyback PS typically has lowest efficiency amongst all PS topologies.

Luminous flux: 500lm >> That is 50% dimmer than a conventional PAR-30 it's supposed to replace. Therefore it can't really replace a PAR-30

Lifespan: 50,000 hours >> This is an outright lie, due to the short life of their PS's electrolytic capacitors.

Conclusion: No one should waste their money buying this product.